Preheat oven to 350°F (175°C). Thoroughly grease a 10-inch bundt pan with butter or baking spray containing flour.
In a medium bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, cloves, and salt until well combined.
In a small bowl, mix brown sugar, cinnamon, and melted butter until it forms a smooth paste for the swirl. Set aside.
In a large mixing bowl, beat granulated sugar and melted butter until light and fluffy, about 2-3 minutes.
Add eggs one at a time, beating well after each addition.
Mix in sour cream, pumpkin puree, and vanilla extract until smooth. Add optional milk if batter seems too thick.
Gradually fold the dry ingredients into the wet mixture until just combined. Do not overmix.
Pour half the batter into the prepared bundt pan. Add half the cinnamon swirl mixture in dollops, then swirl with a knife.
Top with remaining batter, followed by remaining cinnamon mixture. Swirl again with a clean knife or skewer.
Bake for 45-55 minutes, or until a toothpick inserted comes out clean or with a few moist crumbs.
Allow cake to cool in the pan for exactly 10 minutes, then invert onto a cooling rack to cool completely.
For the frosting, beat cream cheese until smooth, add sour cream and beat until combined. Gradually add powdered sugar, vanilla, and salt, adjusting consistency with milk as needed.
Once cake is completely cool, drizzle with the sour cream frosting and serve.
Notes
Room temperature ingredients create a more uniform batter and better texture.
Don’t overmix the batter after adding dry ingredients to avoid a tough cake.
The cake actually improves in flavor after 24 hours as the spices develop.
Unfrosted cake can be stored at room temperature for 3 days; frosted cake should be refrigerated.
For a make-ahead option, freeze unfrosted cake for up to 3 months.
Nutrition facts are estimates and may vary based on ingredients used, portion sizes, and preparation methods.