Fudge-Filled Peanut Butter Cookies

1/2 c. creamy peanut butter
1/2 c. shortening
1/2 c. sugar
1/2 c. brown sugar
1 egg
1-1/3 c. AP flour
1 t. baking powder
1/2 t. baking soda
1 c. chocolate chips
1/4 c. creamy peanut butter
1/8 c. Nutella

Preheat oven to 375 degrees. In a large bowl, beat peanut butter, shortening and sugars on medium speed until fluffy. Beat in egg until smooth. Mix in another bowl, flour, baking powder, and baking soda-beat into other mixture. Shape dough into 48 1 inch balls. On an ungreased cookie sheet, place balls 1 inch apart. Flatten with fork in a criss cross pattern. Bake 4 to 6 minutes. Remove from cookie sheet to cool on wire rack. While cookies are cooling mix together filling. In a small microwavable bowl, microwave chocolate chips for about 1 minute or until softened; stir until smooth. Add peanut butter and Nutella-stir. Cool to room temp. Sandwich pairs of cookies, bottoms together, with 1 T. of chocolate mixture. Let stand until chocolate is firm.