01 -
Preheat the oven to 175°C. Thoroughly butter or spray a 10-cup (2.4 L) Bundt pan, making sure to coat all crevices.
02 -
In a medium bowl, whisk together flour, baking powder, baking soda, salt, and 2 g ground cinnamon until well blended.
03 -
In a large bowl, beat softened butter and granulated sugar with an electric mixer for 3–4 minutes until light and fluffy. Add eggs one at a time, mixing well after each addition. Blend in vanilla extract.
04 -
Add one third of the flour mixture to the butter mixture; mix until just combined. Add half the sour cream; mix gently. Repeat with half of remaining flour, the rest of the sour cream, then the final flour. Mix only until incorporated to avoid overmixing.
05 -
In a small bowl, thoroughly combine brown sugar and 8 g ground cinnamon.
06 -
Pour half the cake batter into the prepared pan and smooth the surface. Evenly sprinkle with half the cinnamon-sugar mixture. Layer remaining batter over, then top with the last of the cinnamon-sugar. Using a table knife, gently swirl in a figure-eight motion three to four times.
07 -
Transfer to the oven and bake for 45–55 minutes, or until a toothpick inserted in the cake emerges clean. Cool in the pan for 10 minutes before inverting onto a wire rack.
08 -
Allow the cake to cool completely. Dust generously with powdered sugar, then slice to serve.