Preheat the oven to 350 F.Place the butter and sugars in a large bowl and beat for several minutes until fluffy and pale in color. Add the peanut butter and beat for a few more seconds until combined. Add the eggs and vanilla and beat another few seconds until combined.In a separate bowl, sift the flour, baking soda, baking powder and salt. Add the flour mixture to the wet mixture and, using a rubber spatula, gently fold to combine. Be careful not to over-stir.Form the dough into 1-inch balls and place them on a non-stick cookie sheet, pressing a grid pattern into them with a fork. Bake for 8-9 minutes.Let the cookies cool on the cookie sheet for 3 minutes before transferring to a wire rack to cool completely.
For the filling: Place the cream cheese, marshmallow cream and Nutella in a bowl and beat until combined.Using a butter knife, spread the filling on the bottom side of one cookie and place another cookie on top.Makes about 32 sandwich cookies.