Equipment
Ingredients
Cake Batter
- 280 g cake flour, sifted
- 300 g granulated sugar
- 15 g natural unsweetened cocoa powder
- 5 g fine sea salt
- 5 g baking soda
- 60 g unsalted butter, softened to room temperature
- 55 g vegetable shortening
- 2 large egg, room temperature
- 240 ml buttermilk, room temperature
- 30 ml liquid red food coloring
- 5 ml vanilla extract
- 15 ml distilled white vinegar
Boiled Milk Frosting (Ermine Frosting)
- 240 ml whole milk
- 35 g all-purpose flour
- 1 g fine sea salt
- 200 g granulated sugar
- 225 g unsalted butter, softened to cool room temperature, roughly 18C to 20C
- 5 ml vanilla extract
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 511 kcal
- Protein
- 5 g
- Carbohydrates
- 66 g
- Fat
- 26 g
- Sugar
- 45 g
- Zinc
- 0.5 mg
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat oven to 175°C (350°F). Grease two 23-cm (9-inch) round cake pans with butter, line the bottoms with parchment paper rounds, and lightly dust the insides with flour, tapping out any excess.
Sift the cake flour and fine sea salt together into a mixing bowl, then whisk briefly to ensure uniform aeration.
In a small mixing bowl, whisk together the natural cocoa powder and liquid red food coloring until a smooth, uniform paste forms without dry cocoa lumps.
Place the softened unsalted butter and vegetable shortening into the bowl of a stand mixer fitted with the paddle attachment. Beat on medium speed for 2 minutes until smooth, then add the granulated sugar and beat on medium-high speed for 4 minutes until pale and fluffy.
Add the room-temperature large eggs one at a time to the creamed butter mixture, beating on medium speed for 1 minute after each addition until fully emulsified.
Add the prepared cocoa and red dye paste along with 5 ml of vanilla extract to the mixer bowl. Beat on medium speed for 1 minute until evenly distributed throughout the batter.
With the mixer running on the lowest speed, add the sifted flour mixture in three alternating batches with the buttermilk in two batches, starting and ending with the flour, mixing each addition only until just incorporated.
In a small mixing bowl, combine the distilled white vinegar and baking soda. Allow the mixture to fizz vigorously, then immediately scrape the effervescing foam into the batter and gently fold with a silicone spatula until thoroughly incorporated.
Divide the batter equally between the two prepared 23-cm pans (roughly 550 g batter per pan) and smooth the tops with a spatula. Bake at 175°C (350°F) for 25 to 30 minutes until a toothpick inserted into the center emerges clean and the cake springs back gently to the touch.
Transfer the pans to a wire cooling rack and cool for 10 minutes. Invert the cakes onto the rack, peel off the parchment paper, and let the layers cool completely to room temperature (about 21°C/70°F), approximately 1 hour.
To prepare the frosting, whisk whole milk, all-purpose flour, and 1 g fine sea salt in a small saucepan over medium-low heat until completely smooth. Cook, whisking constantly to prevent scorching, until the mixture bubbles and thickens into a dense pudding-like roux paste, about 5 minutes at roughly 85°C (185°F).
Scrape the hot milk paste into a clean mixing bowl, press a piece of plastic wrap directly onto the surface to prevent a skin from forming, and cool completely to room temperature (20°C/68°F), about 45 minutes.
In the clean bowl of a stand mixer fitted with the whisk attachment, beat the softened unsalted butter and 200 g granulated sugar on high speed for 5 minutes until pale, light, and mostly smooth.
With the mixer running on medium-high speed, add the cooled milk paste one tablespoon at a time, allowing each addition to incorporate. Once all paste is added, pour in 5 ml vanilla extract and whip on high speed for 4 to 5 minutes until the frosting is pure white, glossy, and billowy like whipped cream.
Using a serrated knife, trim any rounded crowns from the cooled cake layers to create flat tops. Place the first layer cut-side up on a cake stand, spread roughly 200 g of boiled milk frosting evenly across the top with an offset spatula, place the second layer cut-side down, and spread the remaining frosting smoothly across the top and sides.
Refrigerate the assembled cake for 30 minutes at 4°C (40°F) to allow the ermine frosting structure to firm slightly before slicing with a clean, sharp knife.
Chef's Notes
- Natural non-alkalized cocoa powder is critical: its natural acidity reacts with buttermilk and vinegar to support a velvety crumb and prevents the brownish darkening caused by Dutch-process cocoa.
- The authentic Adams Extract formulation relied on a blend of shortening and butter; shortening provides superior moisture retention and a delicate, tender crumb, while butter provides essential dairy flavor.
- Boiled milk frosting (ermine frosting) is an old-fashioned roux-based buttercream. Because sugar is dissolved in the butter and milk matrix rather than added as powdered sugar, the frosting tastes remarkably light, clean, and far less cloying than confectioners sugar frosting.
- For the smoothest ermine frosting, use superfine (caster) sugar, which dissolves more rapidly during the creaming stage with butter than coarse granulated crystals.
Storage
Refrigerator: 4 days — Store in an airtight cake keeper or under an inverted bowl at or below 4°C (40°F) to prevent the delicate ermine frosting from absorbing refrigerator odors.
Freezer: 2 months — Freeze individual unfrosted cake rounds wrapped in plastic wrap and aluminum foil, or freeze sliced frosted portions uncovered until firm before wrapping tightly.
Reheating: Allow refrigerated cake slices to rest at room temperature for 30 to 45 minutes before serving so the butter-rich crumb and frosting achieve their ideal velvet texture; do not microwave as the flour-milk frosting will melt rapidly.
Troubleshooting
Boiled milk frosting curdles, looks separated, or resembles cottage cheese
Cause: The cooked milk-flour paste was too cold when added to the butter, or the butter was too cold to form a stable emulsion
Fix: Warm the outside of the mixer bowl with a warm kitchen towel or brief pass of a hair dryer for 15 seconds, then whip on high speed until smooth
Prevention: Ensure both the butter and the cooled milk paste are at the exact same cool room temperature (18°C to 20°C / 65°F to 68°F) before combining
Boiled milk frosting is soupy and fails to hold peaks
Cause: The cooked milk paste was still warm when added, melting the butterfat
Fix: Place the mixing bowl and whisk in the refrigerator for 15 to 20 minutes to firm the butter, then re-whip on high speed until fluffy
Prevention: Allow the milk roux to cool completely to 20°C (68°F); never rush the process with warm roux
Cake color is dull brownish-red rather than vibrant ruby
Cause: Dutch-process alkalized cocoa was used instead of natural cocoa powder, or insufficient red food dye was incorporated
Fix: Cannot be fixed after baking; the flavor and texture will remain intact despite the darker hue
Prevention: Select non-alkalized natural cocoa powder and measure the full 30 ml of liquid red coloring
Cake crumb is dense, heavy, or poorly risen
Cause: Delay between folding the foaming baking soda and vinegar mixture and putting the pans into the oven
Fix: Cannot be fixed once baked
Prevention: Have the pans greased and oven preheated so the batter enters the heat immediately after folding in the leaveners
Cultural Context
During the Great Depression and World War II, the Adams Extract Company of Texas popularized red velvet cake across American households by distributing tear-off recipe cards packaged with their red food coloring and butter extract. Although contemporary iterations are routinely topped with cream cheese icing, the original mid-twentieth-century Southern standard was paired exclusively with boiled milk frosting (also known as ermine or flour buttercream), providing a featherlight, billowy balance to the mild cocoa cake.
