Spray a 15-cup bundt pan with baking spray with flour; set aside.
In a medium bowl, stir together the apple butter, ¼ cup brown sugar, and pecans; set aside.
In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and cream cheese at medium-high speed for 3-4 minutes, or until smooth. Add the sugar and salt and beat at high speed for 10 minutes, stopping occasionally to scrape down the sides of the bowl. Add the eggs, on at a time, beating well after each addition. Beat in the vanilla. Gradually add the flour, cinnamon and baking powder, beating until well combined.
Spoon one-third of the batter into the prepared pan, making a well in the center of the batter. Spoon half of the apple butter mixture into the well. Top with another third of the batter, making a well in the center of the batter. Spoon the remaining half of the apple butter into the well and top with the remaining batter. Using a knife, pull the blade back and forth through the batter to swirl the apple butter layers. Smooth the top using an off-set spatula.
Place in a cold oven. Bake at 325°F until a wooden pick inserted in the center comes out clean, about 1 hour and 20 minutes. (If the cake begins to brown before it's done, lightly cover with a sheet of aluminum foil.) Let the cake cool in the pan for 20 minutes. Invert the pan on a wire-rack to release the cake and let cool completely.