Spread the cake batter into a greased 9 x 13" baking pan.
Bake at 350° for 15 - 18 minutes until a toothpick comes out with only a few crumbs.
Remove from the oven and spread marshmallows over the top. Return to the oven and bake for an additional 2 minutes.
2 1/2 - 3 c. miniature marshmallows
Cool.
Topping:
Melt chocolate chips over low heat. Or you can melt them in the microwave at 30 second intervals.
1 c. (heaping full) chocolate chips
Add peanut butter and stir until creamy, then stir in the Rice Krispies.
1 c. peanut butter, 1 1/2 c. Rice Krispies
Spread the chocolate layer over top of the cooled marshmallows and set in the refrigerator to chill.
Cut into squares and enjoy.
Store bars in an airtight container in a cool place or in the refrigerator. These bars can also be frozen to keep them fresh longer.
Notes
Variations:If you want to make a chocolate batter for the bottom layer, add 2 Tbsp. of cocoa powder when adding the flour.Instead of using mini marshmallows, you can spread 16 oz. of marshmallow cream over the cooled cake layer. Then spread the topping over the marshmallow cream.If desired, you can add 1/2 c. of chopped nuts to the cake batter before baking.*Nutrition is approximate.