Preheat oven to 350 F.
Grease the sides and bottoms of each cup in the cupcake tray.
Prepare cake mix according to the directions on the box. In this case, we added the cake mix, oil, eggs and water to a large bowl and mixed everything together while well-combined.
Pour batter in cupcake trays and bake for 18-21 minutes (until an inserted fork comes out clean).
Let cupcakes cool completely before frosting.
While cupcakes are cooling, cut the tip of the bag and the insert the 1M Wilton tip, then add the frosting to fill the bag, leaving enough space at the top in order to twist the bag so frosting will not leak out.
Once the cupcakes have cooled completely, frost with vanilla frosting.
Add 2 OREO cookies to each side of the cupcake top to create Mickey's ears.