Peanut Butter Chocolate Bars

I love all things peanut butter, add in a little chocolate, and I'm in heaven...but what woman isn't? I made this recipe yesterday for our small group snack.  

Peanut Butter Chocolate Bars

1 (18.25) package plain yellow cake mix
1/2 cup butter, melted
1 cup creamy peanut butter
2 eggs
1 (12 oz) package semi-sweet chocolate chips
1 (14 ounce) can sweetened condensed milk
2 Tablespoons butter (I recommend melting this prior to adding it to the mix)
2 teaspoons vanilla

Directions:
1) Preheat oven to 325 degrees.
2) Combine cake mix, melted 1/2 cup of butter, peanut butter, and eggs in a large bowl using a mixer or spoon. Press this into a 9X13 pan reserving 1 1/2 cup of the mixture to crumble on top.
3) In a small pot, melt chocolate chips, sweetened condensed milk, and butter. Remove from heat and stir in the vanilla.
4) Spread chocolate mixture over the mixture pressed in the pan and then crumble the 1 1/2 cups of reserved cake mixture on top evenly. (The original recipe tells you to "crumble" - my mix was too dense there really was no "crumbling" possible, so I just placed small circles of the batter.)
5) Bake for 20-25 minutes. Cool completely before cutting into bars. (I cooked mine for the 20 minutes, my toothpick came out clean, but when I cut it later, I thought it was too "brownie-like" so I baked it for another 10 minutes.