Combine pecans, 2 tablespoons sugar, and cinnamon, stirring well. Set aside. Cream butter; gradually add 2 cups sugar, beating well at medium speed of an electric mixer. Add eggs, one at a time, beating after each addition. Combine flour, baking powder, and salt; add to creamed mixture, mixing just until blended. Stir in vanilla. Gently fold sour cream into batter. Pour half of batter into a greased and floured 10-inch Bundt pan. Sprinkle half of the pecan mixture over batter. Repeat procedure. Bake at 350 degrees for 55 to 60 minutes or until a wooden pick inserted in center comes out clean. Cool in pan 10 minutes; remove from pan, and let cool completely on a wire ----