01 - Preheat oven to 350°F. Grease and flour two 9-inch round cake pans, line bottoms with parchment paper.
02 - Sift together flour, sugar, cocoa powder, baking powder, baking soda, and salt in a large mixing bowl.
03 - Add eggs, milk, oil, and vanilla to the dry mixture. Beat on medium speed for 2 minutes until fully incorporated.
04 - Stir in boiling water gradually. The batter will appear thin—this creates the signature moist texture.
05 - Divide batter evenly between prepared pans. Bake for 30 to 35 minutes until a toothpick inserted in the center comes out clean.
06 - Let cakes rest in pans for 10 minutes, then invert onto wire racks. Cool completely before frosting, approximately 1 hour.
07 - Beat softened butter in a large bowl until creamy and light, about 2 minutes. Sift in cocoa powder and mix until smooth.
08 - Add powdered sugar in three additions, alternating with milk. Beat between additions until fluffy and spreadable.
09 - Mix in vanilla extract and salt. Beat on high speed for 1 additional minute for light, airy texture.
10 - Place first cake layer on serving plate. Spread generous frosting layer to edges. Top with second cake layer.
11 - Apply remaining frosting to top and sides. Create signature swoops with offset spatula for the classic Matilda appearance.