Place red velvet cake mix, 1 cup water, 3 eggs and 1/3 cup oil into a large bowl. With a hand mixer on low speed mix until moistened 30 seconds. Place on medium speed and mix for 2 minutes.
Pour batter onto a sheet tray lined with parchment paper, spread out evenly. Bake 20-24 minutes, until toothpick inserted in the middle comes out clean.
Place on a wired rack to cool. When cooled completely, take a small heart shaped cookie cutter and carefully cut out 24 mini hearts and set aside.
Preheat oven to 350 degrees.
Place french vanilla cake mix, 1 cup water, 3 eggs and 1/3 cup oil into a large bowl. With a hand mixer on low speed mix until moistened 30 seconds. Place on medium speed and mix for 2 minutes.
Place 1 Tablespoon of batter into lined cupcake tin. VERY GENTLY place a red velvet heart in the center, do not press down or you will have a circle, not a heart. Cover with about 1 Tablespoon of batter.
Bake for 14-16 minutes, until toothpick inserted in the center comes out clean and they look done on top.
Place butter and half of the sugar in a large bowl. Whip on high speed until sugar is incorporated. Add the remaining sugar and whip on high speed until light and fluffy, 3 minutes.
Add in the vanilla, mix to combine. Add in half of the milk and whip until combined, add remaining milk if mixture is too thick.
Top cupcakes with frosting (I used a large open star tip), decorate with sprinkles if desired, serve and enjoy!
Surprise Inside Heart Cupcakes Recipe found on https://thissillygirlskitchen.com/surprise-inside-heart-cupcakes/ *All nutritional information is approximate and may not be 100% accurate. Please consult a nutritionist for more specific information.