Preheat the oven to 350 degrees. Prepare 3 9-inch round baking pans by spraying with cooking spray. Set aside.
In a large bowl, combine butter, coconut oil, sugar and salt. Mix on high with a handheld or stand mixer until smooth and fluffy, about 3 to 5 minutes.
Add eggs one at a time to the bowl and mix until combined.
In a separate large bowl, mix together flour, baking soda and baking powder with a fork or a whisk.
Turn the handheld or stand mixer to low and add half of flour to the butter mixture. Mix until combined. Add the Greek yogurt and vanilla extract and mix together.
Add the remaining flour to the cake batter and mix until combined.
Evenly add cake batter into baking pans and bake in oven for 25-30 minutes or until a toothpick inserted into the center of the cake comes out clean.
Remove cakes from oven and rest in pans for 10 minutes, or until cake pans are cool to the touch. Then, remove cakes from pans, wrap in plastic wrap and place in the freezer for 1 hour to help cool them down quickly so they're ready to be frosted. If you're not frosting the cake, feel free to enjoy it immediately - no need to cool in the freezer!
For the vanilla cream cheese frosting
In a large bowl, add the butter and cream cheese. Mix together until completely smooth using a handheld or stand mixer.
Add in the vanilla extract and salt. Mix together for about 30 seconds, until combined.
With the mixer on low, slowly add in the powdered sugar by adding a little, mixing it in and then adding some more until the wet and dry ingredients have been combined.
Cover and refrigerate the frosting until ready to use.
To assemble the cake
Before assembling the cake, smooth out every cake layer by slicing off a thin portion of the crown of the cake with a serrated knife in order to make each cake flat and level. Usually, only a small portion of the crown needs to be removed in order for the cake to be somewhat level. It doesn't have to be perfect! Leveling your cake also helps prevent any layers from cracking once they've been stacked on top of each other.
Next, place the first layer of cake onto a cake stand. Top with half of your desired filling. (I used a small 10-ounce jar of strawberry preserves like this one.) Spread filling to the edges of the cake, smoothing evenly. Repeat with second layer. Add the top layer with the bottom facing up and begin frosting.
Add chilled vanilla cream cheese frosting to the top and sides of the 3-layer cake. Using a cake scraper or flat cake knife, smooth the frosting out around the top, edges and sides. To make a "naked cake" as shown in the photos, simply scrape off as much frosting as possible from the sides using your cake scraper
Decorate the top of your cake with sliced fruit, beautiful flowers and serve!
Notes
The Vanilla Cream Cheese Frosting recipe makes enough frosting to cover a fully-frosted cake or enough for two "naked cakes."Recipe adapted from Grandbaby Cakes.