For The Cake: Mix sugar and vegetable oil, add well beaten eggs, mashed banana and vanilla; beat well with electric mixer to combine. MIX: flour, baking soda,baking powder and salt. Slowly add flour mixture to liquid mix and blend well. Stir in apples and pecans. Batter will be stiff.
Pre heat oven to 350 degrees F. Grease and floured a 10" bundt cake pan. Pour filling in to bundt pan and bake 60-70 minutes, or when a tooth pick comes back clean. Removed from oven and let rest on rack for 30 minutes. Turn out on to cake plate and frost with Cream Cheese Frosting.
Cream Cheese Frosting: Cream butter and cream cheese together real well, mix in confectionery sugar and vanilla. Blend until smooth and without any lumps.Stir in chopped pecans and frost cake.
When cake is frosted, take 10 Toasted pecan halves and slightly push in around bottom of cake evenly. These halves will face up and down not around. Push only gently to secure them to icing and space them evenly. Place i pecan half in the middle of back and the middle of front, then middle of each side and fill in between. This will help to keep them spaced evenly. You may also lay a few halves on top of the cake if you choose.