Line an 11 x 7 pan with parchment paper and set aside.
In a medium microwave-safe bowl, add the peanut butter, 2 sticks of butter, powdered sugar and vanilla extract. Microwave on HIGH in 35-second intervals, stirring after each interval, until completely melted and smooth. Remove from microwave.
Pour the melted peanut butter mixture into the parchment lined pan. Spread out evenly with a spatula.
Add the chocolate chips, sweetened condensed milk and 2 tablespoons of butter to a medium microwave-safe bowl. Microwave on HIGH in 35-second intervals, stirring after each interval, until completely melted and smooth. Remove from microwave.
Pour the melted chocolate on top of the peanut butter layer and spread out evenly with a spatula.
Chill for 4 hours to allow the fudge to set.
Cut into a square before serving and ENJOY!!
Notes
* NOTE: To keep your buckeye fudge the freshest, cover with wax paper, foil or plastic wrap and store in a cool, dry place. I prefer to store mine in the refrigerator but you can keep it at room temperature, also. In addition, this fudge freezes really well (for up to 3 months).