Preheat your oven: Start by preheating your oven to 350°F (175°C). Grease and flour your bundt pan to prevent sticking.
Mix dry ingredients: In a large bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt. Set aside.
Cream butter and sugar: In another bowl, beat the softened butter and granulated sugar until light and fluffy. This should take about 3-4 minutes.
Add eggs and vanilla: Beat in the eggs one at a time, mixing well after each addition. Then stir in the vanilla extract.
Incorporate buttermilk and dry ingredients: Alternate adding the dry mixture and the buttermilk to the butter mixture, starting and ending with the dry ingredients. Mix until just combined; do not overmix.
Transfer to pan: Pour half of the batter into the prepared bundt pan. Sprinkle half of the cinnamon-sugar mixture evenly over the batter, then add the remaining batter on top.
Top with cinnamon sugar: Sprinkle the rest of the cinnamon-sugar mixture on top of the batter.
Bake: Bake for 50-60 minutes or until a toothpick inserted in the center comes out clean. Start checking at the 50-minute mark.
Cool: Once baked, allow the cake to cool in the pan for about 10-15 minutes before inverting it onto a cooling rack.
Serve: Let it cool completely before slicing. Enjoy your delicious Snickerdoodle Bundt Cake!
