Directions 14 steps | 120 Minutes
Grease and line a 9 or 10-inch round cake pan that is at least two inches deep. Preheat the oven to 350°F. Measure and prep all ingredients.
Prepare the cake batter. Sift the flour, baking powder, baking soda, and salt together over a piece of parchment paper and set aside.
In the bowl of an electric mixer fitted with the paddle attachment or with a handheld electric mixer, cream the butter until lighter in color.
Add the sugar and mix until light and fluffy.
Mix in the milk and sour cream.
Mix in the eggs, one at a time. Mix in the vanilla extract.
Remove the bowl from the mixer. Use a rubber spatula or large spoon to slowly fold in the flour mixture by hand until just combined. Set aside.
Prepare the streusel. In a medium bowl, combine the flour, brown sugar, powdered sugar, vanilla, cinnamon, salt and butter.
Using a large spoon or a whisk, mix all the ingredients together.
Assemble the cinnamon coffee cake. In the prepared cake pan, pour half of the cake batter.
Top with half of the streusel mixture.
Pour the remaining batter into the cake pan.
Top with the remaining streusel. Bake for 40 minutes, or until the cake is light brown around the edges and a toothpick inserted in the center comes out clean.
Allow the cake to cool. Slice and serve. Enjoy!