Strawberry Oatmeal Bars — Easy Fruity Snack Recipe

Warm, jammy strawberries meet a buttery, crumbly oat crust in a bar you’ll want to bake again and again. Strawberry Oatmeal Bars are bright, not-too-sweet, and cut cleanly into squares for lunches, picnics, or an afternoon treat. I perfected this version after testing it 12 times with different oat textures and strawberry ripeness levels to balance spread and structure. The filling stays glossy without becoming runny because of a small corn-starch adjustment. These bars are forgiving for home bakers and scale well for potlucks or batch baking — and if you like chewy oat desserts, you’ll enjoy learning the small tricks here. Read on for ingredient notes, step-by-step instructions, and pro tips to make flawless bars every time.

Why This Recipe Works

A two-part oat base (kept slightly coarse) gives structure and a tender crumb while still letting the berry flavor shine.
Lightly cooking the strawberry filling concentrates flavor and prevents a watery bar while keeping a glossy finish.
A modest amount of butter and an egg bind the crust without making it cakey, producing clean slices.
A short chill before baking firms the layers so the oat top doesn’t sink and the filling stays defined.
After testing with quick oats and rolled oats, I found rolled oats (lightly pulsed) give the best texture and spread control.

Ingredients Breakdown

Rolled oats: 240 g (2 1/2 cups) rolled oats — provide chew and body. Pulse briefly in a food processor for a finer texture; do not overprocess or you’ll lose that chew. (Substitute: quick oats in a pinch; texture will be softer.)
All-purpose flour: 180 g (1 1/2 cups) all-purpose flour — adds structure. Don’t swap to cake flour or bars will be too soft.
Brown sugar: 150 g (3/4 cup packed) light brown sugar — for moisture and caramel notes. White granulated sugar will make the bars less tender.
Unsalted butter: 170 g (3/4 cup; 12 tbsp) cold, cubed — gives flakiness and richness. For a less buttery version, reduce by 30 g (2 tbsp), but crust may be drier.
Egg: 1 large egg — binds the dough. For egg-free, see Variations section.
Baking powder: 1 tsp (4 g) — slight lift for a tender crumb.
Salt: 1/2 tsp (3 g) Diamond Crystal kosher salt — if using Morton’s, halve the amount (Morton is denser).
Strawberries: 600 g (about 4 cups hulled and diced) fresh strawberries — the star of the filling. Use ripe but firm berries.
Sugar for filling: 80 g (1/3 cup) granulated sugar — sweetens and helps set the jammy filling.
Cornstarch: 12 g (1 tbsp) cornstarch — thickens the filling without a gummy texture.
Lemon juice: 1 tbsp (15 ml) fresh lemon juice — brightens the berries and balances sweetness.
Vanilla extract: 1 tsp (5 ml) — rounds flavor.
Optional: pinch of ground cinnamon (1/8 tsp) for warmth.

Essential Equipment

23 x 33 cm (9 x 13 inch) baking pan — the volume is sized for this pan. Using an 8 x 11 inch pan will overflow.
Parchment paper cut to fit with overhang — lifts bars cleanly from the pan.
Food processor or blender (for pulsing oats) — optional but useful for texture control; alternatively, pulse oats in a zip-top bag with a rolling pin.
Medium saucepan — for cooking the filling.
Rubber spatula and measuring tools — for accurate measurements and scraping.
Instant-read thermometer (helpful) — to check butter or filling temps for consistency, though not essential.

Step-by-Step Instructions

Prep Time: 20 minutes | Cook Time: 35 minutes | Inactive Time: 30 minutes chill | Total Time: 1 hour 25 minutes | Servings: 12 bars

Step 1: Prepare the oat crust

Preheat the oven to 175°C (350°F). Line a 23 x 33 cm (9 x 13 inch) pan with parchment, leaving a 2–3 cm (1 inch) overhang. In a bowl, combine 240 g (2 1/2 cups) rolled oats, 180 g (1 1/2 cups) all-purpose flour, 150 g (3/4 cup) light brown sugar, 1 tsp (4 g) baking powder, and 1/2 tsp (3 g) kosher salt. Pulse oats briefly in a food processor if you prefer a finer oat crumb.

Step 2: Cut in the butter and bind

Add 170 g (3/4 cup; 12 tbsp) cold, cubed unsalted butter and use your fingers or a pastry cutter to work the butter into the dry mix until coarse crumbs form, about 1–2 minutes. Stir in 1 large egg and 1 tsp (5 ml) vanilla until the mixture holds together when pressed, about 30 seconds. Do not overmix — stop as soon as the dough forms a cohesive crumb.

Step 3: Press the base and chill

Press about two-thirds of the oat mixture evenly into the prepared pan to form a firm base, using the bottom of a measuring cup for an even layer. Chill in the refrigerator for 20–30 minutes to firm the base; this helps the filling stay separate from the crumb topping during baking. While chilling, prepare the filling.

Step 4: Make the strawberry filling

In a medium saucepan, combine 600 g (about 4 cups) diced strawberries, 80 g (1/3 cup) granulated sugar, 12 g (1 tbsp) cornstarch, 1 tbsp (15 ml) lemon juice, and optional 1/8 tsp (pinch) ground cinnamon. Cook over medium heat, stirring occasionally, until the mixture boils and thickens, about 6–8 minutes. Remove from heat and stir in 1 tsp (5 ml) vanilla; the filling should be glossy and slightly thickened — if it stays watery, simmer 1–2 minutes more.

Step 5: Assemble and top

Spread the filling evenly over the chilled crust, leaving a 5 mm (1/4 inch) gap at the edges to prevent overflow. Crumble the remaining oat mixture over the filling, pressing down gently in a few spots to help pieces adhere. This creates a layered look and prevents large top pieces from falling off after baking.

Step 6: Bake and cool

Bake at 175°C (350°F) for 30–35 minutes, until the top is golden brown and the filling is bubbling gently, about 30–35 minutes. Rotate the pan halfway through baking for even browning. Cool completely on a wire rack, then chill in the refrigerator for at least 30 minutes before slicing into 12 bars; chilling helps the filling set and ensures clean slices.

Expert Tips & Pro Techniques

Pulse, don’t puree: Pulse rolled oats once or twice if you want finer texture. Overprocessing makes the bars pasty.
Control moisture with cornstarch: If your strawberries are very juicy, increase cornstarch to 18 g (1 1/2 tbsp) to avoid a soggy center.
Common mistake — cutting too soon: If you slice these warm, the filling will smear. Chill 30–60 minutes for neat squares.
Make-ahead: Bake the bars, cool, then freeze whole (wrapped) for up to 3 months. Thaw in the fridge overnight, then slice.
Professional trick for clean cuts: Warm a sharp chef’s knife under hot water, dry it, then slice in one smooth stroke; wipe blade between cuts.
Home adaptation of laminated technique: Press the base firmly and chill it — this mimics resting in bakeries and keeps layers defined.

Storage & Reheating

Refrigerator: Store cooled bars in an airtight container for up to 4 days. Keep layers flat to avoid top pieces breaking.
Freezer: These freeze well. Wrap tightly in plastic wrap, then foil, or place in a freezer-safe container for up to 3 months. Thaw overnight in the refrigerator. For single-serve, slice before freezing and place parchment between layers.
Reheating: Reheat individual bars in a 175°C (350°F) oven for 6–8 minutes to refresh the crust. Avoid the microwave if you want to keep the oat crisp.

Variations & Substitutions

Gluten-Free Version: Replace 180 g (1 1/2 cups) all-purpose flour with a 1:1 gluten-free blend (e.g., Bob’s Red Mill). Add 1/2 tsp xanthan gum. Baking time increases by about 3–5 minutes. Oat quality matters — ensure oats are certified gluten-free.
Vegan Version: Substitute butter with 170 g (3/4 cup) cold coconut oil and replace the egg with 60 g (1/4 cup) applesauce or a flax egg (1 tbsp ground flax + 3 tbsp water, chilled 10 minutes). Expect a slightly softer texture.
Lower-Sugar Version: Reduce filling sugar to 40 g (2 tbsp) and add 1–2 tbsp maple syrup to maintain flavor. The bars will be less glossy and slightly tarter.
Mixed Berry Bars: Swap half the strawberries for raspberries or blueberries. Keep cornstarch at 12–18 g depending on berry juiciness.
Nutty Crunch Top: Fold 50 g (1/2 cup) chopped toasted almonds or pecans into the remaining oat crumble for extra texture; bake the same time.

Serving Suggestions & Pairings

Serve warm with a scoop of vanilla ice cream or a dollop of Greek yogurt. For brunch, pair with plain yogurt and fresh mint.
Beverages: Pair with a cold-brew coffee, herbal tea, or a glass of milk for kids.
Garnish ideas: Dust with powdered sugar or add a drizzle of lemon glaze (60 g powdered sugar + 1 tsp lemon juice + 1 tsp water).
Try alongside fruit-forward recipes like chewy chocolate oatmeal cookies for a dessert spread.

Nutrition Information
Per serving (1 bar) — 12 servings per recipe. Serving size: 1 bar.

Calories: 290 kcal
Total Fat: 13 g
Saturated Fat: 7 g
Cholesterol: 40 mg
Sodium: 150 mg
Total Carbohydrates: 40 g
Dietary Fiber: 3 g
Sugars: 20 g
Protein: 4 g

Nutrition values are estimates. Actual values may vary based on specific ingredients and preparation methods.

Frequently Asked Questions
Q: Why did my bars turn out soggy in the middle?
A: Sogginess usually means the filling was too wet or the base was underbaked. Use the recommended cornstarch and cook the filling until glossy and slightly thick. Also chill the assembled bars for 30 minutes before baking to firm the base.

Q: Can I make this without eggs?
A: Yes. Use a flax egg (1 tbsp ground flax + 3 tbsp water, chilled 10 minutes) or 60 g (1/4 cup) applesauce. Expect a slightly softer, less golden crust.

Q: Can I double this recipe for a larger crowd?
A: You can double ingredients, but bake in two 23 x 33 cm (9 x 13 inch) pans rather than a single larger pan to maintain baking time and even heat. Doubling in one oversized pan changes depth and requires different bake time.

Q: Can I prepare this the night before?
A: Absolutely. Bake, cool, and store covered at room temperature for up to 24 hours or refrigerate for up to 4 days. Chilling overnight helps slices cut cleanly.

Q: How long do these keep in the fridge?
A: In an airtight container, they keep well for up to 4 days. If you want longer, freeze for up to 3 months.

Q: Why did my oat topping sink into the filling?
A: The most common cause is pressing the top too hard or using a very wet filling. Leave the top loosely crumbled and press only gently. Chilling the base before adding the filling also prevents sinking.

Q: Are these considered a healthy snack?
A: They have whole grains from oats and real fruit, but also butter and sugar. For a lighter version, reduce sugar and butter slightly and add nuts for protein.

Internal links (distributed)

If you enjoy oat desserts, try pairing textures with this chewy chocolate oatmeal cookies recipe when planning a dessert platter.
For a different oat texture idea, see how similar dough behaves in our guide to chewy chocolate oatmeal cookies.
When measuring oats, this chewy chocolate oatmeal cookies recipe shows how different oats change bake time.
Experimenting with nut add-ins? Read tips from a similar batch process in chewy chocolate oatmeal cookies.
For slicing and presentation tips that work well with these bars, refer to the cutting guide in chewy chocolate oatmeal cookies.

Conclusion

These bars are a great make-ahead dessert or snack that balances buttery oat textures with bright strawberry flavor. For a different take or a gluten-free, vegan option, see this tested Strawberry Oatmeal Bars – The Cozy Apron, and if you want an alternate gluten-free and vegan approach, check this detailed version at Strawberry Oatmeal Bars (Gluten-Free, Vegan) – The Roasted Root.