Ingredients
Equipment
Method
Prep and assemble
- Preheat oven to 350°F and line a 9x13 baking dish with parchment paper; leave overhang for easy lifting if you want. Keep parchment in place so the bars release cleanly for slicing.
- Combine old-fashioned oats, all-purpose flour, granulated sugar, brown sugar, baking powder, and salt in a large bowl. Mix until the dry ingredients are evenly distributed with no dry pockets.
- Cut in softened unsalted butter until the mixture resembles coarse crumbs. The texture should look sandy with larger clumps that can be pressed.
- Press half of the oatmeal mixture firmly into the prepared baking dish. Use steady pressure to form a compact base layer that bakes evenly.
- Combine sliced fresh strawberries, granulated sugar, lemon juice, and cornstarch in a bowl. Stir until the cornstarch is well dispersed and the berries look glossy.
- Spread the strawberry filling evenly over the base layer. Aim for an even thickness so every bar has bright red fruit in the center.
- Spread the remaining oatmeal mixture over the strawberries and press gently. Keep the top crumbly rather than packed hard so it bakes up golden.
Bake and cool
- Bake at 350°F for 30-35 minutes until the top is golden brown. Look for browned edges and a firm, set crumble surface.
- Allow to cool for 15 minutes before cutting into bars. Letting them rest helps the filling thicken so slices hold their shape.
- Dust with powdered sugar before serving. Add it right before eating for a neat, snowy finish over the golden crumble.
Notes
For tight, clean bar slices, press the bottom layer firmly and keep the top layer only gently compressed—this preserves the crumbly crumble texture. Store covered in the refrigerator for up to 4 days; freeze bars in a single layer (then wrap) for up to 2 months. If you want a lighter option, swap half the all-purpose flour for whole-wheat flour for more fiber while keeping the same crumble method.