Peanut Butter S'mores Cookie Bars

1/2 cup butter, softened
3/4 cup sugar
1 egg
1 tsp vanilla extract
1 cup graham cracker crumbs
1 1/3 cup flour
1 tsp baking powder
1/4 tsp salt
1 1/2 cup milk chocolate chips
1/3 cup peanut butter
3 cups miniature marshmallows

Heat oven to 350 F. Grease an 8-inch square baking pan.

In a mixing bowl, beat the butter and sugar until well blended. Add egg and vanilla, beat well. Stir together graham cracker crumbs, flour, baking powder and salt. Add the flour mixture to the butter mixture, mixing until well combined. Press half of the dough in the prepared pan. Bake 15 minutes.

3. Sprinkle chocolate chips over baked layer, drop peanut butter by spoonfulls over the chocolate chips, using a toothpick to swirl everything around so the bottom cookie layer is evenly covered.  Sprinkle with marshmallows and scatter the remaining dough over the marshmallows, forming the top layer. Bake 10 to 15 minutes or just until lightly browned. Cool completely in pan on wire rack. Cut into bars.