Instructions:

1. Preheat oven to 350ºF.
2. Apply non-stick spray to a 10-inch bundt pan or a 10-inch tube pan and set aside.
3. Using a paddle attachment on your stand mixer, cream until light and fluffy:
• 12 TBS butter, unsalted , room temperature
• 1 ¹/₂ cup granulated sugar
4. Mix in one at a time:
• 3 eggs, extra-large , room temperature
5. Mix in:
• 1 ¹/₂ tsp vanilla extract
• 1 ¹/₄ cup sour cream
6. In a separate bowl, mix together:
• 2 ¹/₂ cup cake flour , * (not self-rising)
• 2 tsp baking powder
• ¹/₂ tsp baking soda
• ¹/₂ tsp salt
7. With the mixer on low, add the flour mixture to the batter until just combined.
8. Finish stirring with a spatula to be sure the batter is completely mixed. Do not over mix the batter once the flour has been added. The result could be a dry cake.
9. In a small bowl, make the streusel by placing in a small bowl:
• ¹/₂ cup all-purpose flour
• 1 ¹/₂ tsp cinnamon, ground
• ¹/₄ tsp salt
• 3 TBS butter, unsalted , cold & cut into pieces
• ¹/₄ cup brown sugar, light , packed
10. Pinch together with your fingers until it forms a crumble.
11. Stir in:
• ³/₄ cup walnuts , chopped
12. If using a tube pan, spoon half the batter into the prepared pan and spread it out with a knife. Sprinkle with 3/4 cup streusel. Spoon the rest of the batter in the pan, spread it out, and scatter the remaining streusel on top.
13. If using a bundt pan, sprinkle 3/4 cup streusel into thepan. Then, spoon half the batter into the pan and spread it out with a knife. Sprinkle with remaining streusel. Spoon the rest of the batter in the panand spread it out.
14. Bake for 50 to 60 minutes, or until a skewer inserted in the center comes out clean.
15. Remove to a cooling rack to cool for 30 minutes.
16. Carefully transfer the cake, streusel side up, onto a serving plate.
17. To glaze, blend until smooth in a small bowl:
• ¹/₂ cup powdered sugar
• 2 TBS maple syrup
18. If glaze is too thick, add a little water sparingly.
19. Drizzle the glaze over the cake, allowing it to drip down the sides.