Cinnamon-Laced Coffee Cake

Preheat oven to 375 degrees F (190 degrees C). Spray a 9x13-inch baking dish with cooking spray. Sprinkle cinnamon sugar into the bottom of prepared baking dish.

Combine brown sugar walnuts softened butter flour and cinnamon for streusel mixture in a bowl; mix with a fork until crumbly.

Mix flour baking powder and salt for batter together in a separate bowl. Beat eggs in a third bowl using an electric mixer until frothy; add white sugar and melted butter and beat until creamy. Add milk sour cream and vanilla extract and beat until smooth. Stir flour mixture into milk-butter mixture until batter is well blended.

Spread 1/2 of the batter into the prepared baking dish; top with 1/2 of the streusel mix. Spread remaining batter over streusel layer and top with remaining streusel.

Place dish on the center rack in the preheated oven; bake until a fork inserted in the center comes out clean 15 to 20 minutes.