Preheat the oven to 350° Fahrenheit and line a cookie sheet with parchment paper. Set aside. Line 48 mini muffin tins with mini cupcake liners. Also set aside.
Bake the red velvet cake:
Mix the red velvet boxed cake mix according to manufacturer’s directions. Pour the cake mix onto lined cookie sheet and spread evenly. Place in the oven and bake until a toothpick inserted in the middle comes out clean, about 12-18 minutes, depending on your oven. Remove cookie sheet from the oven and allow to cool for about 5 minutes. Invert cake onto a cutting board and allow to cool completely. With a heart shaped cookie cutter, cut 48 hearts. Size doesn’t matter. You can go tiny or medium. It’s all good. Line the hearts on a plate and place in the fridge until ready to use. Please note, you will have tons of red velvet cake scraps. Save them in a plastic Ziploc bag and use them for truffles, trifles, or mini desserts! I placed mine in the freezer for truffles. Fun!
Bake the cupcakes:
In a large bowl, combine flour, salt, and baking soda. Mix quickly with a fork to combine, and set aside.
In a bowl of an electric mixer fitted with a paddle attachment, mix the butter and sugar over medium speed until light and fluffy, about 3 minutes. Add eggs one at a time beating well after each addition. Stop and scrape the mixer as needed. Reduce the speed to low and add the vanilla bean paste and vanilla extract.
Add the flour mixture, alternating with the milk, starting and ending with the flour. Stop and scrape the mixer. Turn the mixer back to low and mix until just combined. Remove bowl from the mixer and give it a couple of folds, making sure you scrape the bottom of the bowl to ensure cake batter is evenly mixed.
Remove cut-out red velvet hearts from the fridge. With a cookie scoop, scoop cake batter into cupcake liners, leaving about 1/8 inch of space. Take a red velvet heart and push it into the center of each cupcake. Make sure the red velvet heart is completely covered by cake batter.
Place muffin tins in the oven and bake until cake lightly browned and toothpick or cake tester inserted in the sides of several cupcakes comes out clean, anywhere from 12-18 minutes depending on your oven.
Remove the muffin tins from the oven. Leave the cupcakes in the muffin tins for about 3 minutes, then transfer to a wire rack and allow to cool completely before frosting the cupcakes. As the cupcakes cool, make the Vanilla cream cheese frosting.
Vanilla Cream Cheese Frosting:
In a bowl of an electric mixer fitted with a whisk attachment, combine butter and cream cheese. Mix on medium/high speed until combined. Stop the mixer and add the confectioners’ sugar and vanilla extract. Mix on low speed until the confectioners’ sugar is combined with the cream cheese/butter mixture. Increase the speed to medium/high and mix until light and fluffy, about 2-3 minutes. Stop the mixer, taste, and add more confectioners’ sugar if you prefer a thicker frosting and more vanilla extract if you prefer a more pronounced vanilla flavor. Add the heavy cream and mix until thickened, another 15-20 seconds.
Stop the mixer and transfer frosting to a piping bag fitted with a decorative tip. Place in the fridge until ready to use.
When ready to use, pipe frosting on each mini cupcake. If you prefer more frosting on each cupcake, feel free to double the recipe.