Peanut Butter Marbled Brownies
1 box (19 to 20 ounces) brownie mix
1/2 cup creamy peanut butter
1/4 cup sugar
1 1/2 teaspoons flour
1 egg
Prepare brownie batter according to package directions. Spread into 9 x 13-inch pan that has been coated on bottom with no-stick cooking spray; set aside. In small bowl, beat remaining ingredients until smooth and creamy. Place in small reclosable freezer-weight plastic bag. Snip off 1/2-inch tip from one corner. Pipe peanut butter mixture over batter in even lines about 1 inch apart. Pull table knife through lines of peanut butter mixture, pressing knife almost all the way to bottom of pan, pulling in alternate directions about 1 inch apart. Bake in 350°F. oven for 28 to 30 minutes, or until wooden pick inserted in center comes out nearly clean. Cool completely before cutting.