Cake isn’t usually my dessert of choice because I feel like a lot of cakes honestly fall short of what I’m looking for. This cake is exactly the type of cake I want when I am in the mood for cake. The cake itself has both butter and oil for the most incredible, moist texture. There is also a lot of vanilla flavor in it, making it so much more than just a vessel for frosting!
This post contains product affiliate links. I may receive a commission if you make a purchase after clicking on one of these links.
I was torn between a chocolate and vanilla frosting for this cake, but in the end went with vanilla since that seemed to be the strong preference on Instagram – don’t worry though, I’ll be working on a chocolate frosting to share soon! I got the cake just how I wanted it on round one, but the frosting took a few tries. In the end, I got a vanilla frosting with the perfect texture and a delicious vanilla flavor. It has just the right balance of sweetness as well that I love from a homemade buttercream frosting.
This cake tastes great at any temperature. It can be sliced and enjoyed right after you frost it, but it will also taste incredible from the fridge or straight from the freezer. I find that other cakes can dry out in the fridge, but with this one it tastes just as great the next day after being in the fridge overnight, sliced and stored in an airtight container.

I highly recommend using a stand or hand mixer for both your cake batter and frosting. When making your batter, it’s extremely important that your butter, eggs and milk are all at room temperature. Your butter should be out of the fridge for a few hours, or softened quickly in the microwave for about 5 to 10 seconds. Your eggs and milk should come out of the fridge about an hour before you plan to start. If any of these ingredients are too cold, your butter may curdle when making your batter – if this happens, it’s okay to continue on but know that it may cause your cake to sink a bit when baking. If you don’t have a mixer on hand, you could melt the butter for your cake and use room temperature butter for your frosting and hand whisk each but the best result will come from a stand mixer and paddle attachment for both your cake and frosting.
One last note, sprinkles are totally optional in this recipe. I baked the cake batter both ways, and it tasted and baked great with and without the sprinkles. Personally, I love the look of the rainbow sprinkles and I think they add a nice texture on top of the frosting as well, but if sprinkles aren’t your thing just skip that part of the recipe!
Double Vanilla Birthday Cake

Equipment
- 9×9 square pan (or 8×8 and increase the bake time)
- Stand mixer with paddle attachment *You can use a hand mixer instead. A whisk can work too, but your cake batter butter will need to be melted and your frosting butter will need to be soft to the touch at room temperature.
- Medium bowl
Ingredients
For the best results, I highly recommend using the gram measurements provided
Cake batter
- 8 tablespoons (1/2 cup) (113g) unsalted butter at room temperature
- 2 tablespoons vegetable or neutral oil
- 3/4 cups (144g) granulated sugar
- 1/3 cup (64g) light brown sugar
- 2 teaspoons vanilla extract
- 2 large eggs
- 2/3 cup milk (I used 2%)
- 1 1/4 cup (150g) all purpose flour
- 1 teaspoon baking powder
- 1/4 teaspoon baking soda
- 1/4 teaspoon salt
- 1/4 cup rainbow sprinkles
Frosting
- 8 tablespoons (1/2 cup) (113g) unsalted butter at room temperature
- 1 1/4 cup (150g) powdered sugar
- 1 tablespoon milk (I used 2%)
- 1 teaspoon vanilla extract
- 2 tablespoons rainbow sprinkles
Instructions
- Make your cake. In your stand mixer with the paddle attachment, add your room temperature butter and oil. Turn your mixer on for about a minute until your butter and oil come together completely.
- Next, add both sugars and turn your mixer back on for about a minute or two. Use a spatula to scrape down the sides of your bowl and the paddle attachment.
- Add in your vanilla and one egg. Turn your mixer on and add your second egg only once the first has been fully incorporated. Continue to run your mixer at a high speed for about a minute or two. Pause halfway through to scrape down the sides of your bowl and paddle to ensure you don’t miss any unmixed pockets.
- Then, it’s time to incorporate your milk and dry ingredients. Measure your milk (ensure it’s at room temperature), and in a separate bowl, mix together your dry ingredients, flour, baking powder, baking soda, and salt. Pour about half of your milk into your butter and sugar mixture and turn your mixer back on at a slow speed then up to a high speed. Pause, and add in about half of your dry ingredients and let your mixer run again to combine. Scrape down the sides of your bowl and paddle. Go through this one more time, add in the rest of your milk and mix until fully combined, then the rest of your dry ingredients and mix until your batter just comes together. Finally, add in your rainbow sprinkles, and let your mixer run at a low speed to disperse your sprinkles. Be sure to scrape down to the bottom of your bowl, and you can finish mixing by hand with your spatula to make sure everything comes together without over mixing.
- Line a 9x9in square pan (or you can use an 8×8 pan and increase the cook time a bit) with parchment paper. I recommend ensuring all sides of the pan are lined, or you can lightly grease. Pour your batter in and spread flat and into the edges.
- Place your cake into the oven to bake for about 30 minutes. It should be lightly golden on the top, and if you shake the pan when it comes out it should just barely jiggle.
- Once baked, allow your cake to cool at room temperature for about an hour, and then place it in the fridge for an hour prior to frosting. Note: if you don’t plan to frost right away, scroll to the bottom for guidance! In the meantime, clean or swap out your stand mixer bowl and paddle attachment so you’ll be ready for your frosting.
- Make your frosting and finish your cake. Place your butter into your stand mixer with the paddle attachment. Let your mixer run for about a minute or two until your butter softens and smooths.
- Next, add in your powdered sugar. Turn your mixer on slowly and pulse until your sugar begins to mix into your butter. Turn your mixer up to the highest speed and let it run for a few minutes. Pause, scrape down the sides of your bowl and paddle attachment and then add in your milk and vanilla extract. Slowly turn your mixer back on and up to its highest speed and let it mix for about 3-5 minutes, pausing halfway through to scrape down your bowl and paddle attachment.
- Dollop your frosting onto your completely cooled cake and use your spatula or any flat tool to spread your frosting to your liking. Sprinkle on your remaining rainbow sprinkles, slice and enjoy!
- Serve and store your cake. I recommend cutting your cake into 16 or 9 squares. You can cut and enjoy your cake right away, or store the slices in the fridge in an airtight container. If you plan to serve it the next day, you can also cover your cake with plastic wrap and keep it in the fridge and slice the next day. Your sliced cake will remain fresh for a couple of days as well in the fridge if stored in an airtight container.














