Preheat oven to 350°. Beat butter at medium speed with a heavy-duty electric stand mixer 1 to 2 minutes or until creamy. Gradually add both sugars, beating well. Add eggs, 1 at a time, beating just until blended after each addition. Add mashed bananas and vanilla, and beat at low speed just until combined.
Stir together flour and next 4 ingredients in a small bowl. Gradually add flour mixture to butter mixture, beating at low speed just until blended. Stir in 1/2 cup pecans. Spread batter in a greased and floured 15- x 10-inch jelly-roll pan.
Bake at 350° for 20 to 25 minutes or until a wooden pick inserted in center comes out clean. Cool completely on a wire rack (about 1 hour).
Spread cake with Cream Cheese Frosting. Top with Glazed Banana Slices, if desired. Sprinkle with remaining 1/2 cup chopped toasted pecans.