Cinnamon Streusel Coffee Cake

Preheat the oven to 350F degrees.

In the bowl of a standing mixer or with a handheld mixer, cream together the butter and sugar for 4-5 minutes, until light and fluffy.

Add the eggs, one at a time, making sure to fully incorporate before adding the next one. Add the vanilla.

In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.

Alternate between adding the flour mixture and the sour cream to the butter/sugar mixture until combined.

In a small bowl, combine the brown sugar, walnuts, cinnamon and melted butter, and stir to combine well.

Pour half the batter into a greased bundt pan, and smooth down with a spatula as this batter is thick and fluffy.

Sprinkle the brown sugar mixture all over the batter in the bundt pan and pat it down lightly.

Pour in the remaining batter and smooth down with a spatula.

Place the bundt pan in the oven and bake for 45-50 minutes, until a toothpick inserted in the center comes out clean.

Remove from the oven, and allow to cool for 15 minutes. Flip cake out of pan into a cooling rack. If necessary, run a sharp knife carefully around the edges of the pan to loosen the cake to flip.