Beat margarine, sugars, peanut butter and egg until light and fluffy.
In a separate bowl combine the dry ingredients.
Add to creamed mixture and mix well.
Roll out into a rectangle on a piece of plastic wrap.
Cover with a second piece of plastic wrap while you prepare the filling.
Filling
Heat Saco Chocolate Chunks and butter in a double boiler, stirring until chocolate is melted. Uncover the cookie dough you previously rolled out and spread chocolate mixture over the surface. Beginning at the longest edge, roll up like a jelly roll.
Wrap in plastic wrap or wax paper and refrigerate several hours or over night. Bake in 375°F preheated oven.
Cut roll into ¼ inch slices and place on ungreased baking sheet.
Bake for 10-12 minutes or until lightly browned.
Remove from baking sheet immediately and cool on wire racks.