- 6 T unsalted butter, melted
- ½ C butter room temp., plus more for greasing pan
- ½ t baking powder
- 1 C confectioners sugar
- ½ t pure vanilla extract
- 1 ¾ C all-purpose flour, plus more for pan
- 2 large eggs
- 2 cups of any fresh berries (if frozen, thaw and drain first)
- ½ C packed brown sugar
- ½ t salt
Preheat oven to 350°.
Butter an 8-inch square baking pan. Line bottom with parchment paper, leaving an overhang on two sides; butter and flour paper, tapping out excess.
Make topping: In a medium bowl, whisk together melted butter, brown sugar and ¼ teaspoon salt; add 1 cup flour, and mix with a fork until large moist crumbs form. Refrigerate topping until ready to use.
In a medium bowl, whisk together remaining ¾ cup flour, baking powder, and remaining ¼ teaspoon salt; set aside. In a large bowl, using an electric mixer, beat room-temperature butter, confectioners sugar, and vanilla until light and fluffy; add eggs, one at a time, beating well after each addition. Reduce speed to low; mix in flour mixture. Spread batter evenly in pan; sprinkle with berries, then sprinkle on chilled topping.
Bake until golden and a toothpick inserted in center comes out with moist crumbs attached, 40 to 45 minutes. Cool completely in pan. Using paper overhang, lift cake onto a work surface; cut into 16 squares.