Banana Bundt Cake

1 (18.25 ounce) box yellow cake mix
1 small box vanilla instant pudding
3/4 cup vegetable oil
3/4 cup water
4 eggs
1 teaspoon vanilla extract
1 teaspoon butter extract
1/2 cup nuts (optional)
2 mashed ripe bananas

Mix all ingredients together for 4 to 6 minutes. Pour into greased and floured Bundt pan. Bake at 350 degrees F for 35 to 40 minutes.