6 tablespoons unsalted butter, room temperature
1 ½ cups flour
1 ½ teaspoons baking powder
½ teaspoon salt
1 cup plus 2 tablespoons sugar
½ cup milk
1 teaspoon vanilla extract
½ pound strawberries, hulled and halved
½ pound blueberries
Preheat oven to 350 degree F. Grease a 10 inch pie plate with butter.
In a stand mixer, on medium-high speed, beat together butter and 1 cup sugar until pale and fluffy. On medium-low speed, mix in egg, milk, and vanilla.
On low speed, slowly add in flour mixture about ½ cup at a time. You may need to use a spatula to scrape sides of bowl down.
Pour batter into buttered pie plate. Arrange strawberries and blueberries on top. Place strawberries cut side down. Sprinkle remaining 2 tablespoons sugar over berries.
Bake for 10 minutes and then reduce temperature to 325 degrees F. Bake for additional 60 minutes until cake is golden brown and firm to the touch.
Allow cake to cool in pie plate. Store cake at room temperature loosely covered for up to 2 days or refrigerate.