Cinnamon Streusel Coffee Cake: Tender

Instructions:

1. Preheat oven to 350°F (175°C) and grease a 9x13 inch baking pan or line it with parchment paper.
2. In a small bowl, whisk together 1 cup flour, 3/4 cup brown sugar, and 2 tsp cinnamon.
3. Rub the cold, cubed butter into the streusel ingredients using a fork or fingertips until the mixture resembles wet sand with pea-sized clumps.
4. Stir in the chopped nuts and set the streusel aside in the refrigerator.
5. In a medium bowl, whisk together 2 cups flour, baking powder, and salt.
6. In a large bowl, beat softened butter and granulated sugar until light and fluffy, approximately 2-3 minutes.
7. Add eggs one at a time, beating well after each, then stir in the vanilla extract.
8. Alternate adding the flour mixture and the sour cream to the butter mixture, starting and ending with flour, mixing on low speed until just combined.
9. Spread half of the batter into the prepared baking pan.
10. Sprinkle the middle layer of cinnamon (1 tsp) and brown sugar (2 tbsp) evenly over the batter.
11. Spread the remaining batter over the cinnamon sugar layer and top evenly with the prepared streusel.
12. Bake for 40 minutes or until a toothpick inserted into the center comes out clean.