Heat treat the cake mix by placing in a heat proof bowl, and microwaving for 30 second increments until the mix reaches an internal temperature of 160°F. Can also toast in an oven preheated to 350°F for 5-7 minutes.
Add the room temperature butter, white sugar, brown sugar, flour, cake mix and vanilla extract to mixing bowl. Mix over low speed until dough forms. Will seem crumbly at first, if dough is not coming together use your hands to form. At this point add in the sprinkles and mix to combine.
Form the cake batter dough into small 'pattys' using about 1/2 a tablespoon of dough. Place the pattys onto a cookie sheet lined with parchment paper. Place the cookie sheet into the fridge for at least 10 minutes to chill.
Microwave the white baker's chocolate for 30 seconds, remove from microwave to stir and microwave again for 30 seconds. Stir and if needed microwave for another 30 seconds or less until completely melted. Stir in the oil.
Spoon a small amount of melted chocolate into the bottom of the mini muffin liner, top with the cake batter and then spoon an additional small amount of chocolate on top. Spread the chocolate around with the bottom of the spoon to ensure all sides are coated.
Place the cake batter cups into the fridge to cool and harden for at least 10 minutes.
Remove from muffin liners and enjoy!