1. Preheat the oven to 400° F. Grease a 10-in bundt pan (I just use the reside left on the butter wrapper).
1. Beat the butter and sugar (keep the 1/4 c out) with an electric mixer until light and fluffy, then add the eggs one at a time, then the vanilla. Finally, add the yogurt.
2. In a separate bowl, combine the flour, baking powder, and baking soda, then add to the wet mix.
3. Combine the remaining sugar with the cinnamon in another separate bowl.
4. Pour about half the batter into the bundt pan. Then sprinkle the cinnamon sugar mixture onto the batter. Then cover the cinnamon sugar mixture with the rest of the batter.
5. Bake at 400° F for 8 minutes, then lower the temp to 350° F and bake for another 40 minutes, or until a tester comes out clean.
6. Let the cake cool completely, then slide a silicone spatula into the large grooves to loosen it up, flip the pan over and jiggle the cake onto a plate.