- 1 box yellow cake mix
- 1 cup water
- 3 eggs
- ½ cup creamy peanut butter
- ⅓ cup butter, softened
- ½ cup chocolate-flavored syrup
- 3 tablespoons creamy peanut butter
- 2 to 3 tablespoons milk
- 1 cup powdered sugar
- 2 tablespoons chocolate-flavored syrup
- 20 miniature chocolate-covered peanut butter cup candies, unwrapped and cut in half
- Spray a 5- to 6-quart oval slow cooker with cooking spray. In large bowl, beat cake mix, water, eggs, ½ cup peanut butter and the butter with electric mixer on low 30 speed seconds, then on medium speed 2 minutes, scraping bowl.
- Remove ⅔ cup of the batter to medium bowl; stir in ½ cup chocolate syrup to make chocolate fudge batter.
- Spoon ½ of the peanut butter batter into the slow cooker, followed by all of the chocolate fudge batter. Top with remaining peanut butter batter. Swirl with a knife in a circular motion.
- Cover; cook on High heat setting 1 hour 45 minutes to 2 hours 15 minutes or until toothpick inserted in center of loaf comes out clean. Turn off slow cooker; uncover, and remove ceramic base from cooker to cooling rack. Let cool 15 minutes.
- In medium bowl, beat 3 tablespoons peanut butter and 2 tablespoons milk with whisk until smooth. Add powdered sugar; mix until smooth. If necessary, gradually add additional 1 tablespoon milk until glaze is desired consistency. Spread peanut butter glaze over cake; drizzle with the chocolate syrup. Sprinkle peanut butter cups over top of cake.