In a large bowl, cream together butter, peanut butter, brown sugar, and white sugar with an electric mixer on medium speed for 30 seconds. Add in vanilla and egg and continue to mix for 10 seconds.
Add baking soda and mix on low speed for 10 seconds. Add flour and continue to mix until all flour is incorporated.
Scoop & roll dough into 2 tablespoon sized balls and place each in a greased muffin tin.
Bake at 350 degrees for 8 minutes. Remove from oven, and immediately press one Unreal Snacks Peanut Butter Cup into the center of each cookie.
After a few minutes, the chocolate of the Unreal Snacks Peanut Butter Cup will start to melt. Once this happens, gently place a heart sprinkle onto the top of each one.
Place pan in refrigerator for 10-15 minutes to help the chocolate re-harden.
Allow to cool before removing the cookies from the pan. For easy removal, use the tip of a spoon to help lift out the cookies.