Preheat oven to 350°F. Coat cake panswith nonstick spray. Line bottom of panswith parchment; coat paper.
Whisk flour,baking soda, and salt in a medium bowl.Using an electric mixer, beat sugar, butter,and brown sugar in a large bowl until lightand fluffy, about 3 minutes.
Add eggs one ata time, beating to blend between additionsand occasionally scraping down sides andbottom of bowl. Beat in vanilla.
Add dry ingredients; beat on low speedjust to blend.
Add bananas and sour cream;beat just to blend. Fold in mini chips. Dividebatter evenly among pans; smooth tops.
Bake cakes until a tester inserted into thecenter comes out clean, about 35 minutes.
Transfer to wire racks; let cool in pans for10 minutes. Invert cakes onto racks; peel offparchment and let cool completely.
Using an electric mixer, beat first4 ingredients in a medium bowl until a lightand fluffy frosting forms, 2–3 minutes.
Place 1 cake on a platter.
Spread 1 1/4 cupsfrosting over.
Place remaining cake on top.Cover top and sides of cake with remainingfrosting.
Garnish with chocolate chips andkisses. DO AHEAD: Cake can be made 2 daysahead. Cover and chill.
Let stand at roomtemperature for 1 hour before serving.