Dessert Recipe

Prepare oven and pan

Preheat oven to 350°F (175°C). Grease an 8- or 9-inch square baking pan (or a similar round pan) and line with parchment paper leaving an overhang for easy removal.

Mix dry ingredients

In a medium bowl, whisk together 1.5 cups flour, 1 cup granulated sugar, 1.5 tsp baking powder, and 1/2 tsp salt until evenly combined.

Combine wet ingredients

In a separate bowl, whisk together 2 large eggs, 1/2 cup melted butter, 1/2 cup milk, and 1 tsp vanilla extract until smooth.

Make the batter

Pour wet ingredients into dry ingredients and stir with a spatula just until combined and no large streaks of flour remain. Do not overmix. The batter should be thick but spreadable. Spread the batter evenly into the prepared pan using an offset spatula or the back of a spoon.

Prepare fruit filling

If using larger strawberries, hull and quarter them. In a medium bowl toss 2 cups mixed berries with 1/4 cup sugar, 1 tbsp cornstarch, and 1 tbsp lemon juice until berries are evenly coated. Let sit 5–10 minutes so juices develop.

Assemble fruit on batter

Gently spoon the berry mixture over the spread cake batter, distributing fruit and juices evenly. Some juice will sink into the batter—this is fine and will help keep the cake moist.

Make crumb topping

In a bowl combine 3/4 cup flour, 1/2 cup packed light brown sugar, 1/2 cup old-fashioned oats, 1/2 tsp ground cinnamon, and 1/8 tsp salt. Add 1/2 cup cold cubed butter and cut it into the dry mixture with a pastry cutter or fork until mixture resembles coarse crumbs with some pea-sized pieces.

Top the fruit

Evenly sprinkle the crumb topping over the berries, covering as much of the surface as possible.

Bake

Bake in the preheated 350°F (175°C) oven for 35–45 minutes, or until the crumb topping is golden brown and a toothpick inserted into the center (avoiding large fruit pockets) comes out with only moist crumbs (not wet batter). If the top browns too quickly, tent loosely with foil for the last 10–15 minutes.

Cool

Remove from oven and set the pan on a wire rack. Cool at least 20–30 minutes in the pan so the filling sets; for cleaner slices, cool to near room temperature.

Serve

Use the parchment overhang to lift the dessert from the pan. Dust with powdered sugar if desired and cut into squares. Serve warm or at room temperature with vanilla ice cream or whipped cream if desired.