1 (16 ounce) package yellow cake mix
1 (4.5 ounce) package instant chocolate pudding mix
1 (16 ounce) package chocolate covered pecan halves
1/4 cup dark corn syrup
2 teaspoons vanilla extract
2 teaspoons peanut butter
1/2 cup buttermilk
1 1/2 cups rolled oats
1/2 cup buttermilk
1/3 cup butter
Preheat oven to 350 degrees F (175 degrees C). Grease and flour 3/4 cup of prepared and frozen cake mix.
Mix yellow cake mix, pudding mix, and pecan halves. Stir in 1/4 cup of corn syrup, vanilla extract, peanut butter, buttermilk, and buttermilk. Pour into prepared and frozen cake layers.
Let the cake cool—about 8 to 10 hours—in the refrigerator. Cut into 2 (5 or 7 inch) pieces, and return smaller pieces to oven. Cake will take longer if refrigerated.