Preheat oven to 350°F/175°C. Line three 4-inch or two 6-inch cake pans with parchment paper, then grease them with non-stick spray. This recipe turns out best with light-colored metal pans - preferably aluminum!

This recipe can be made by hand with a whisk or with a hand mixer. I prefer making it with a whisk.

In a large bowl, whisk together 1 cup flour, 1 cup sugar, 1 tsp baking powder, and ¼ tsp salt.

Add ¼ cup of melted butter, ¼ cup oil, and 1 egg into the dry ingredients and whisk until combined. The batter will be thick.

Then mix in ½ cup buttermilk, 1 tsp vanilla extract, and gel food coloring if you want to color the cake layers. Mix until combined and scrape the sides and bottom of the bowl with a rubber spatula as needed. Then, continue to mix the batter for an additional 30 seconds to make sure everything is properly combined. This will also help lighten the texture of the cake layers - this recipe uses the reverse crumbing method, so I promise this won't overmix the batter!.

Divide batter evenly between the prepared cake pans. Bake for 32-35 minutes on the middle rack of the oven, or until a toothpick comes out with a few moist crumbs. Allow the pans to cool for 10 minutes, then run an offset spatula around the perimeter of the pan to separate the cake from the pan.

Place cake layers into the freezer for 20 minutes to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers from the pans.

Use a serrated knife to level the tops of the layers, then set aside. If you're making these in advance, wrap and freeze them at this point.

While the cake layers bake and cool, make the vanilla buttercream frosting. Beat ¾ cup butter on medium speed for 30 seconds with either a hand mixer or a stand mixer fit with a paddle attachment.

Mix in 2 tsp vanilla extract or vanilla bean paste and ¼ tsp fine salt on a low speed.

Gradually mix in 3 cups of powdered sugar and 1 Tbsp + 1 tsp of heavy cream. Scrape the sides and bottom of the bowl with a rubber spatula to make sure everything is properly mixed together.

Continue to mix on low speed for a few minutes, until the desired consistency is reached.

If the frosting seems too thick, add additional cream (1 tsp at a time). If the frosting is too thin, add more powdered sugar (a quarter of a cup at a time).

If you want to color the buttercream, add in the gel food coloring once the frosting is fully made, and beat on low until it's evenly colored.

Stack and frost cake layers on a small plate or cake stand using a dab of frosting to help stick the first cake layer in place.

Add an even layer of buttercream between each cake layer with a small offset spatula.

Add a thin coat of frosting around the cake that fully covers the cake layers. Smooth using a bench scraper, then chill the cake in the fridge (20 minutes) or freezer (5 minutes) until the frosting is firm to the touch.

Add a second, thicker layer of frosting to the cake, and smooth using a bench scraper. If you're struggling to get smooth sides on your cake, I share all my tips and tricks in this smooth cake tutorial.

Then decorate as desired! I used a Wilton 1M frosting tip (any open star tip would work great)to pipe some fun swirls on top of the cake and topped them with nonpareil sprinkles.