CUPCAKES: In a bowl, beat oil, brown and granulated sugar together using a hand or stand mixer medium speed until creamed for about 2-3 minutes. Add the eggs one at a time beating well every after additions at low speed. Add the mashed bananas and vanilla extract and beat for another minute still at low speed.

Combine flour, baking soda, cinnamon and salt together in a separate bowl. Add the dry ingredients to the wet ingredients one cup at a time alternating with some buttermilk until all are added. Mix well after every addition. Add the chocolate chips and cashew nuts last and mix until well blended.

Preheat oven to 350°F/170°C. Line 2 12- count cupcake pans with cupcake liners. Spoon the batter evenly into the cupcake liners filling about a three-fourths of each cup. Place one pan on the middle rack and the other on the bottom and bake for 18-20 minutes or until a toothpick inserted in the middle of a cupcake comes out clean. The pans may need to change places in between baking for them to bake evenly and at the same time. Do the same for the last batch (6 cupcakes). Allow to cool completely before frosting.

PEANUT BUTTER BUTTERCREAM FROSTING: Using a hand or stand mixer at medium speed, cream together the butter and peanut butter until smooth for about 2 minutes. Add the sifted powdered sugar and vanilla extract and beat for a minute. Add the cream and beat at high speed for about 2 minutes.

CARAMEL BUTTERCREAM FROSTING: Using a hand or stand mixer at medium speed, cream together the butter and caramel until smooth for about 2 minutes. Add the sifted powdered sugar and salt and beat for a minute. Add the cream and beat at high speed for about 2 minutes.