The Cake of Your Dreams, aka Portillo's Chocolate Cake

August 17, 2024

This chocolate cake is unbelievably moist, tender, and soft. The cake layers have a soft rich crumb and intense chocolate flavor. All pulled together by a smooth, velvety, rich, chocolate fudge frosting. Inspired by Portillo’s chocolate cake.

Portillo’s is a restaurant chain that is found in various locations, such as Illinois, Indiana, Arizona, and California. The Restaurant started when Dick Portillo invested in a small trailer in 1963 to open the first Portillo’s hot dog stand in Villa Park, IL. Shortly after, the chocolate cake was introduced to the menu and soon became everyone’s favorite. Sold in large slices, the cake is a must to try if you haven’t before. However, I don’t live near a Portillo’s, so this recipe satisfies my cravings and is JUST like the original.

Rumor has it that Portillo’s uses mayonnaise in their cake. Yes. You heard it right, MAYO in chocolate cake. It sounds really strange, but when you look at the ingredients, scientifically it isn’t so weird!

Mayonnaise is an emulsion of eggs, oil, and either lemon juice or vinegar. All of those ingredients are pretty common to find in a cake recipe. Learn more about what mayonnaise does for this cake here

In order for your cake to turn out the most moist and fudgy as possible, here are my tips.

Do not overbake your cakes: You know that they are done when you insert a toothpick and it comes out clean, or with a few moist crumbs.
Chill, chill, chill! It can be hard to have the patience to wait for the cake to cool down before frosting, but trust me it will make decorating a whole lot easier. You don’t want to end up with one pile of runny frosting and broken cake layers. Chilling the cake after spreading on the middle layer of frosting is highly recommended!
Mixing: When the dry ingredients are added to the batter, be cautious of how fast you’re mixing- only just enough to bring the batter together. Otherwise, an overworked batter can lead to a tough cake.

Happy Baking! As always, remember… whenever you’re in the kitchen, you’re not only a baker, but a chemist too!

10 - 12 slices
Total Time: 3 hours
Prep Time: 2 hours (chill 20 minutes)
Bake Time: 37 minutes

Ingredients

For the Cake:

1 ¾ cups (230g) all purpose flour
¼ cup (30g) cornstarch
1 cup (100g) unsweetened cocoa powder
2 tsp baking soda
1 tsp baking powder
½ tsp kosher salt
1 cup (200g) granulated sugar
1 cup (205g) dark brown sugar, packed
½ cup (108g) vegetable oil
1 cup (230g) mayonnaise
3 large eggs + 1 egg yolk
½ cup (128g) milk
1 tbsp vinegar
2 tsp vanilla extract
1 cup (240g) hot coffee (or 1 cup hot water + 2 tsp instant espresso powder)

For the Fudge Frosting:

1 cup (226 g) whipping/heavy cream
4 tsp cocoa powder - unsweetened, Dutch process preferred
2 ½ cups (400 g) semisweet chocolate
1 cup ( 226 g) unsalted butter
1 ⅓ cups (170g) powdered sugar
½ tsp instant coffee
½ tsp salt
2 tsp vanilla extract

Directions

Preheat the oven to 350F and prep 2 9″ cake pans and a cupcake pan. Grease the inside and line the bottom with parchment paper. If you have them, wrap the pans in damp cake strips and set aside.
In a medium bowl, whisk together the flour, cornstarch, cocoa powder, baking soda, baking powder, and salt. Set aside.
In a measuring glass, add the milk and stir in the vinegar and vanilla. Set aside.
In a large mixing bowl, whisk together the sugars, oil, and mayo, followed by the eggs and egg yolk.
Mix in the milk mixture.
Pour in half of the dry ingredients and whisk to combine.
Pour in the hot coffee and whisk to combine, followed by the remaining dry ingredients. The batter should be very thin and liquid. Evenly distribute the batter between the two pans. There should be enough batter left to make four cupcakes.
Bake for 35-40 minutes or until a toothpick in the center comes out clean with a few moist crumbs.
Allow the cakes to cool in the pan for about 10 minutes, then run a knife around the edges and turn out onto a cooling rack. Cool the cakes completely before frosting, either at room temperature or in the refrigerator.
To make the frosting, place a saucepan or pot over a medium heat and add in heavy cream. Heat until you start to see little bubbles forming around the edges of the pan. The cream shouldn’t be boiling. Turn the heat down to low and add in the remaining ingredients and continue to gently whisk until all the solid ingredients are melted and you have a very smooth mixture.
Pour the mixture into a heat proof bowl, and then cover the top with cling wrap so that the cling wrap is directly touching the top of the frosting. This will prevent a skin from forming as it cools down.
Place the frosting into the fridge for 2 hours to allow it to set.
Before assembling, make sure the cake layers are completely cooled.
Level off the top of each cake layer if needed.
Lay one layer down on a cake turntable and spread a layer of frosting on top. Lay the next cake layer on top, repeating the process.
Once all the layers are stacked, place the cake in the refrigerator for about 20 minutes to allow those layers to set. Once set, cover the entire outside of the cake with frosting.
Now, enjoy!

Notes

The original recipe found here uses 3 8” pans. The famous Portillo’s chocolate cake uses 2 9” cake pans and I wanted to replicate the cake as best as I could. However, using 2 9” pans leaves some remaining batter to make around 4 cupcakes. If you decide to use 3 8” pans, bake for 30 - 35 minutes instead.

If you end up leaving your frosting in the fridge for too long and it’s very hard, then either let it come to room temperature, or if you’re in a rush, heat the frosting in the microwave for 10 second bursts at a time, mixing in between each burst until you reach your desired consistency. On the other hand, if your frosting is still too soft, just leave it in the fridge for longer to firm up.

Recipes adapted from https://butternutbakeryblog.com/moist-chocolate-cake/ and https://cakesbymk.com/recipe/rich-chocolate-cake/

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