Preheat oven to 350 degrees F. Lightly spray 10-inch fluted tube pan with cooking spray; set aside. In bowl stir together flour, baking powder, baking soda, salt, and cinnamon. Set aside.
In large mixing bowl beat butter with an electric mixer on low to medium speed 30 seconds. Add sugar; beat until fluffy. Add eggs, one at a time, beating on low to medium speed 1 minute after each addition and scraping bowl frequently. Beat in sour cream and vanilla. Alternately add flour mixture and milk to butter mixture, beating on low speed after each addition just until combined.
Divide batter into two bowls. Stir melted chocolate into half the batter until well combined. Stir peanut butter into remaining half until well combined.
Alternately drop spoonfuls of batter into prepared pan. Use a small metal spatula or butter knife to gently swirl the batters together (no not overmix).
Bake in preheated oven 40 to 45 minutes or until wooden toothpick inserted near center comes out clean. Cool 15 minutes on wire rack. Remove cake from pan; cool thoroughly on wire rack. Drizzle cake with half of the Salted Caramel Glaze. If desired, sprinkle with Sea Salt. Pass remaining sauce.