- Preheat oven to 325°F. Place a Flexipan Fluted Square Mold on a Medium Perforated Baking Sheet.
- With an electric mixer cream butter and sugar until light and fluffy. Beat in eggs one at a time. Set aside.
- In a separate mixing bowl, whisk together flour, baking soda, baking powder and salt. With the electric mixer on stir, slowly add the flour mixture one spoonful at a time.
- Add sour cream and vanilla and stir for an additional 30 seconds. Set aside.
Brown Sugar Streusel Instructions:
- Mix brown sugar, nuts, cinnamon, and flour until incorporated.
- Stir in melted butter until crumbly.
- Set aside.
Coffee Cake Instructions:
- Add 1/3 streusel mix into Fluted Square Mold already place on Medium Perforated Baking Sheet.
- Add half of the cake batter. Add another 1/3 of streusel.
- Top with remaining batter.
- Finish with remaining streusel.
- Bake in preheated oven for 55-65 minutes or until cake pulls away from pan, insert toothpick in middle of cake, if comes out clean, then the cake is done.
- Let cake cool cake on a rack in pan 30 minutes.
- Turn cake out onto a serving plate.