Prep the pans and oven. Heat oven to 350°F (175°C). Grease and line two 8-inch round cake pans with parchment. Lightly dust with cocoa or flour and tap out the excess.

Whisk the dry ingredients. In a large bowl, whisk flour, sugar, cocoa, malted milk powder, baking powder, baking soda, and salt until no streaks remain.

Mix the wet ingredients. In a separate bowl or large measuring cup, whisk buttermilk, oil, eggs, and vanilla until smooth.

Combine wet and dry. Pour the wet ingredients into the dry. Stir with a spatula until just combined—some small lumps are fine.

Add hot coffee. Slowly pour in the hot coffee while stirring. The batter will be thin; that’s what makes the cake moist and tender.

Divide and bake. Split the batter evenly between pans. Bake 28–34 minutes, or until a toothpick comes out with a few moist crumbs.

Cool completely. Let cakes cool in pans 10 minutes, then turn out onto racks. Peel off parchment and cool fully before frosting.

Make the frosting. Beat butter on medium speed until creamy and pale, 2–3 minutes. Add powdered sugar, cocoa, and malted milk powder. Mix on low to combine, then add vanilla, salt, and 3 tablespoons cream. Beat on medium-high until fluffy, adding more cream 1 tablespoon at a time until spreadable.

Assemble. Place the first cake layer on a stand. Spread a generous layer of frosting on top. Add the second layer and cover the top and sides with frosting. Smooth or create swoops, then garnish if you like.

Set and serve. Let the cake sit 20–30 minutes to set the frosting. Slice with a warm knife for clean cuts.