In a large mixing bowl, cream together butter and sugars until fluffy. Add eggs, one at a time, beating well. Add vanilla and butter flavor. In small bowl, combine flour, cinnamon, allspice, nutmeg, baking soda, and salt. Add to creamed mixture alternately with applesauce. With wooden spoon, fold in apples and pecans.
Pour into a greased and floured 10" Bundt pan. Bake at 350 degrees for 55-60 minutes until toothpick inserted near the center comes out clean. Cool for 10 minutes before turning out of pan. Allow to cool completely on wire rack.
For glaze, in a small saucepan, melt butter and brown sugar over low heat. Stir in half and half. Cook and stir until mixture comes to a boil. Boil for 1 minute. Remove from heat. Whisk in powdered sugar and vanilla until smooth, about 1 minute. Pour over cake. Serves 12.
Notes
*Unless otherwise noted, all of my recipes use "salted" butter. If using unsalted butter, you may want to increase the salt in this recipe.