Preheat your oven to 350°F (175°C) and grease a 10-cup bundt pan.

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

In a large bowl, beat together the butter, granulated sugar, and brown sugar until pale and fluffy.

Add the eggs one at a time, then mix in the vanilla extract and sour cream until smooth.

Gradually add the dry ingredients to the wet mixture, mixing just until combined.

In a small bowl, mix together sugar and ground cinnamon for the cinnamon mixture.

Layer one-third of the batter in the bundt pan, followed by half of the cinnamon mixture and repeat, finishing with the last of the batter.

Bake for 50 to 60 minutes, or until a toothpick comes out clean.

Cool the cake in the pan for about 10 minutes before inverting onto a wire rack.

Optional: Prepare the glaze by melting butter, then whisk in powdered sugar and milk.