Be sure to preheat your oven to 350 degrees F. Place cupcake liners in your cupcake or muffin pan.

In a large mixing bowl with a hand mixer or your stand mixer bowl using the paddle attachment, mix together all of your ingredients except the peanut butter cups for minute or two until well mixed.

Place 3 Tbsp of cake batter in each cupcake liner. Take one frozen peanut butter cup and place in the center of each cupcake on top of the batter, press down a little bit.

Bake for 18 to 22 minutes or until several cupcakes pricked with a toothpick come out clean. Do not prick the cupcake where the peanut butter cup is inserted. There will be a slight indentation or hole where the cupcake is sunken in from the peanut butter cup, you'll fill that with icing. Allow the cupcakes to cool in the pan for 5 to 10 minutes.

Remove cupcakes from the pans and place them on a cooling rack & let them cool all the way. While the cupcakes are baking you can make the buttercream icing.

In your stand mixer bowl using the paddle attachment, mix thoroughly the softened butter and peanut butter on low to medium speed. Turn off your mixer and in two batches, add the powdered sugar and mixing until well blended. Be careful, the powered sugar can go everywhere!

Add vanilla and 3 to 4 tablespoons of milk a little bit at a time while blending on low speed. Blend until well combined. You'll start to see the icing pull from the sides of the bowl. Add a little bit more milk to get to the right thinness (to your preference). Keep blending, higher the speed, until nice and fluffy, about 5 to 7 minutes.

Using a big round tip and decorator bag, pipe icing onto cooled cupcakes and top with a mini on each cupcake.

I used a smaller box of instant pudding because that's what I told my husband but it worked out just fine.

I don't like tons of icing on my cupcakes so one batch of peanut butter icing actually worked for 2 batches of cupcakes for me.

I used a Tbsp measuring spoon, I really need to get a cookie scoop or a ice cream scoop that measures out to 3 Tbsp.

I actually ended up with 30 cupcakes in the batch...so even more to share or to keep for yourself! I don't like putting 3 cupcake pans in the oven so I'll usually fill up two of them (24 cupcakes), bake them and then fill one with the remaining 6 cupcakes.

I prefer to make buttercream icing in a stand mixer but you can make it with a hand mixer in a large bowl, it may take a little longer to make but it's worth it!

I actually left the cupcakes on a cooling rack covered with a kitchen towel and placed the icing in the fridge overnight. When you're ready to frost your cupcakes, allow to the icing to sit on the counter for at least 20 to 30 minutes. I even added splashes of water to it to make it even more fluffy before piping the icing onto the cupcakes.