If you like oatmeal chocolate chip muffins, then you’ll love the flavor and texture in cake form! I adapted my oatmeal chocolate chip muffin recipe into this three-layer, six-inch oatmeal chocolate chip cake with dark chocolate buttercream frosting and brown sugar frosting. There are a lot of steps involved, but I promise the effort is worth it. Decorate it like I did, or choose your own adventure!
If you don’t own 6-inch pans, I recommend these.
An optional ingredient I love for this recipe is extra virgin blood orange olive oil. If you can’t find any then don’t worry about it. I buy mine from a speciality store in Charlotte called Pour Olive that sells other unique olive oils and balsamic vinegars. Consider looking for something similar in your area!
(This post contains affiliate links. I may receive a small commission, at no cost to you, if you make a purchase through a link. My full affiliate disclosure and privacy policy is available here.)
All of my recipes are gluten free, but you can make then gluten-full. In this case simple sub the flour and the oats. (This is my favorite gluten free flour.)
Also be sure to use quick cooking oats and not old-fashioned.
There are detailed instructions in the recipe below, but here are a few tips:
Use a food scale to evenly divide the cake batter. This might seem like an unnecessary step, but it makes achieving uniform layers so much easier. If you don’t have a food scale, use measuring cups.
It’s a little difficult determining when the cake is done because it’s dense like a muffin, and the melty chocolate chips might make you think the batter is wet when it’s not. You’ll know it’s done when the top is lightly browned and slightly cracked.
I like to freeze the cake before decorating. But be sure to level the cake before putting it in the freezer. Eat the scraps or turn them into cake truffles! Just mix the scrap crumbs with a little bit of frosting (add 1 teaspoon of frosting at a time, until the crumbs hold their shape). Roll into balls, chill in the fridge for 1 hour, and then dip in melted chocolate. I recommend Ghirardelli chocolate melting wafers.
Back to the cake: When making the brown sugar frosting, keep in mind that the brown sugar will cool more quickly if after 30 minutes you pour it into a different heatproof bowl.
Don’t forget to sift the powdered sugar! If you don’t own a sifter, use a mesh colander.
The frosting recipe also yields more than you actually need, but I found it’s easier to have more when you’re scraping the edges. Save the extra for cupcakes or graham cracker sandwiches (which was my mom’s favorite way to use up excess frosting).
Use Wilton tip #2D to pipe the rosette on top of the cake. Starting in the center, apply even pressure on the piping bag and slowly pipe in a clockwise circle until you reach the outside edges.
This cake takes a while to defrost, so if you froze it overnight you’ll need to wait a few hours before you can easily cut it. Let it defrost in the refrigerator and then bring it to room temperature before cutting a slice. Trust me, it’s much easier that way!
Cake decorating is a time-consuming process, but it’s well worth the effort! Tag me @rosesandwhiskers on Instagram if you try it and use the hashtag #rosesandwhiskers. Feel free to ask if you have questions.
Happy baking! 
Oatmeal Chocolate Chip Cake
Ingredients
- 2 cups gluten free 1 to 1 baking flour or substitute all-purpose flour for gluten-full cake
- 2 tsp baking powder
- 1/2 tsp baking soda
- 1/2 tsp salt
- 1/2 cup unsalted butter softened to room temperature
- 1/2 cup vegetable oil
- 1 1/2 cups packed light brown sugar
- 2 large eggs room temperature
- 1 1/2 cups sour cream room temperature
- 2 tsp vanilla extract
- 1 tsp extra virgin blood orange olive oil optional
- 1/2 tsp almond extract
- 2 1/2 cups gluten free quick cooking oats or substitute gluten-full oats
- 2 cups bittersweet chocolate chips
Brown Sugar Frosting
- 1/2 cup unsalted butter
- 1/2 cup Crisco
- 1 1/2 cups packed light brown sugar
- 1/3 cup heavy cream
- 5 1/2 cups powdered sugar sifted
- 2 tsp vanilla extract
- 2-3 tbsp whole milk
- gel food coloring optional
Dark Chocolate Buttercream Frosting
- 1/2 cup unsalted butter softened to room temperature
- 1/2 cup Crisco
- 4 cups powdered sugar
- 1/2 cup dark cocoa powder
- 3 tbsp whole milk
- 3 tbsp heavy cream
- 1 tsp vanilla extract
- chocolate chips and sprinkles for decorating optional
Instructions
- Preheat the oven to 350°F (176°C) and grease three 6-inch round cake pans. (See the recipe notes.)
- In a medium bowl, whisk together the flour, baking powder, baking soda and salt.
- In a large bowl, cream the butter, vegetable oil and sugar on high speed until light and fluffy. Beat in the eggs one at a time, until incorporated. Mix in the sour cream, extracts and olive oil on medium speed. The mixture will be soft and creamy.
- Stir the flour mixture into the sugar mixture on low speed, until just combined. Fold in the oats and chocolate chips by hand.
- Divide the batter evenly between the three pans and bake for 38-42 minutes until the tops are lightly browned and a toothpick inserted into the center comes out clean. (Be wary of the chocolate chips, which might make it difficult to test doneness.) Let the cakes rest in the pans for 10 minutes before removing to a wire cooling rack. (See the recipe notes.)
- Carefully level the cakes once they've cooled completely. Wrap them tightly in plastic wrap and aluminum foil and freeze for at least one hour. You can also freeze them overnight.
Decorating the Cake
- Begin making the brown sugar frosting while the cake is chilling. Mix the butter, Crisco, brown sugar and heavy cream over medium heat, stirring constantly, until the sugar dissolves and the butter and Crisco melt. Let the mixture come to a boil and then immediately remove it from the heat and pour into a heatproof bowl. Let it cool to room temperature, about an hour.
- Make the dark chocolate buttercream. Cream the butter and Crisco until light and fluffy. Add in 1/2 of the powdered sugar and the cocoa powder. Mix on low speed until incorporated and then beat on high speed until creamy. Add in the rest of the powdered sugar, the vanilla extract, the milk and heavy cream. Mix on low speed until incorporated, and then beat on high speed until creamy and fluffy.
- Remove the cakes from the freezer and unwrap them. Begin assembling the layers. Put one layer on a cake board and spread 1 cup of frosting on top. Don't worry if the frosting hangs over the edges of the cake. Add another cake layer and another cup of frosting. Top with the remaining layer and cover the cake with a crumb coat. (See the recipe notes.) Freeze the cake for 30-60 minutes.
- Finish making the brown sugar frosting once the cake has been chilling for 30 minutes. Pour the brown sugar mixture into a different heatproof bowl and then stir in the sifted powdered sugar on low speed until incorporated. Add 2 tbsp of milk and the vanilla, and beat on high speed until creamy and fluffy. Add up to 1 more tbsp of milk if needed, adding 1 tsp at a time. Optional: mix in gel food coloring.
- Take the cake out of the freezer and add a layer of brown sugar frosting to the sides and top of the cake. Spread it on using an offset spatula and use the spatula or a scraper to smooth the edges. Wipe the blade clean frequently to achieve a smoother finish. Tip: Use a warm blade. Run it under warm water and wipe it dry.
- Pipe a large rosette on the top of the cake using the brown sugar frosting and a Wilton #2D tip. Top with sprinkles. Place chocolate chips around the top edge of the cake and down the sides for a "drip." Pipe a chocolate border around the bottom of the cake using the #2D tip. Garnish with brown sugar frosting stars using Wilton tip #21.
- Cover and store in the refrigerator. Best enjoyed at room temperature. Enjoy!
