Polish Babka Cake

Details

Ingredients

• 1 ¼ cups all-purpose flour
• 2 teaspoons baking powder
• ¾ cup potato starch
• ¾ cup unsalted butter, at room temperature
• 2 tablespoons unsalted butter, at room temperature
• 1 ½ cups confectioners' sugar
• 1 teaspoon vanilla sugar
• 4 eggs, separated
• 3 tablespoons sour cream, or more to taste
• ½ lemon, zested and juiced
• 1 tablespoon almond extract
• 2 tablespoons raisins
• 1 ½ tablespoons butter
• 3 tablespoons dried bread crumbs