Chocolate-Peanut Pinwheels

Chocolate Dough - Combine flour, cocoa powder, baking soda and salt in a bowl; beat butter, sugar, egg and vanilla in a second bowl at medium speed until combined - At low speed, beat in four mixture; flatten into 1" thick disk, wrap and chill until firm (about 1 hour) Peanut Dough - Combine flour, baking soda and salt in a bowl; beat butter, peanut butter, sugar, egg and vanilla in a second bowl at medium speed until combined - At low speed, beat in flour mixture; flatten into 1" thick disk, wrap and chill until firm (about 1 hour) Cookies - Divide chocolate dough and peanut dough in half; on floured wax paper, using floured rolling pin, roll out each portion dough into 12" x 6" rectangle - Invert 1 portion of peanut butter dough on 1 portion of chocolate dough; remove wax paper - Starting from long side, roll up dough; repeat with remaining dough - Wrap rolls in wax paper and chill until firm (about 1 hour) - Coat baking sheets with cooking spray; cut dough into 1/4" thick cookies and place on sheets - Bake at 350°F until lightly browned (about 8 to 10 minutes); transfer to rack to cool