Step 1: Preheat your oven to 325°F (160°C). Grease and flour a 10-12 cup Bundt pan thoroughly.
Step 2: In a medium bowl, whisk together the all-purpose flour, baking powder, and salt. Set aside.
Step 3: In a large mixing bowl, using an electric mixer, cream together the softened butter and 8 ounces of softened cream cheese until light and fluffy, about 2-3 minutes.
Step 4: Gradually add the granulated sugar to the butter and cream cheese mixture, beating until well combined and fluffy, scraping down the sides of the bowl as needed.
Step 5: Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next. Stir in the vanilla extract.
Step 6: Alternately add the dry ingredient mixture and the sour cream (or buttermilk) to the wet ingredients, beginning and ending with the dry ingredients. Mix on low speed until just combined, being careful not to overmix.
Step 7: In a small bowl, combine the light brown sugar and cinnamon for the swirl.
Step 8: Pour about half of the cake batter into the prepared Bundt pan. Sprinkle half of the cinnamon sugar mixture evenly over the batter.
Step 9: Carefully spoon the remaining batter over the cinnamon layer, then sprinkle the remaining cinnamon sugar mixture on top. Use a knife or skewer to gently swirl the cinnamon mixture into the batter in a circular motion.
Step 10: Bake for 60-75 minutes, or until a wooden skewer inserted into the center of the cake comes out clean.
Step 11: Let the cake cool in the pan on a wire rack for 10-15 minutes before inverting it onto the rack to cool completely.
Step 12: While the cake cools, prepare the Cream Cheese Glaze. In a medium bowl, beat together 4 ounces softened cream cheese, powdered sugar, milk (1-2 tablespoons, adjust for desired consistency), and 1/2 teaspoon vanilla extract until smooth.
Step 13: Once the cake is completely cool, gently warm the caramel sauce for easy drizzling.
Step 14: Drizzle the cream cheese glaze generously over the cooled cake, allowing it to drip down the sides. Then, drizzle the warm caramel sauce and sprinkle with chopped pecans. Slice and serve!