Ingredients:

– 1 1/2 cups all-purpose flour – 1/2 cup white sugar – 1/2 cup light brown sugar – 1 teaspoon baking powder – 1/2 teaspoon baking soda – 1/2 teaspoon salt – 1/2 cup unsalted butter, softened – 2 tablespoons vegetable oil – 2 large eggs – 1 teaspoon pure vanilla extract – 1/2 cup sour cream – 1 1/2 cups fresh blackberries, halved – 1/2 cup all-purpose flour (for topping) – 1/4 cup light brown sugar (for topping) – 1/4 cup cold cubed unsalted butter (for topping) – 1/2 cup powdered sugar (for glaze) – 1 tablespoon milk (for glaze) – 1/2 teaspoon vanilla extract (for glaze)

Steps:

1. Prepare the Pan and Oven. Set your oven to 350°F (177°C) and let it preheat fully so the heat is stable when the pan enters. 2. Assemble the Streusel Topping. Combine the flour, light brown sugar, salt, and cold, cubed butter in a medium bowl. 3. Combine the Dry Base. Sift the all-purpose flour, white sugar, light brown sugar, baking powder, baking soda, and salt into a large bowl. .................. Read Full Recipe In Our Site...