Beat together the first 5 ingredients at low speed with an electric mixer 2 minutes or until blended. Pour batter into a greased 15x10 inch jelly roll pan.
Bake at 350°F for 15-20 minutes or until a wooden pick inserted in center comes out clean. Cool in pan on a wire rack 2 hours. Make Caramel Pecan frosting and pour immediately over cooled cake in pan, and spread quickly to cover cake.
Place chopped pecans in a single layer in a shallow pan. Bake at 350°F for 6 minutes or until lightly toasted.
Bring butter and brown sugar to a boil in a 3 1/2 quart saucepan over medium heat, whisking constantly (about 2 minutes). Remove from heat and slowly whisk in buttermilk.
Return mixture to heat, and bring to a boil. Pour into bowl of a heavy duty electric stand mixer. Gradually add powdered sugar, vanilla extract and almond extracts,beating at medium-high speed until smooth(about 1 minute). Stir in pecans. Use immediately.