Red velvet layer cake with cream cheese frosting

Prep the pans with baking spray or butter and either flour or cocoa powder to dust.

Mix the flour, kosher salt and baking soda in a large bowl and set aside.

Cream the room temperature butter well -- a dark cake shows any unmixed clumps.

Add the granulated sugar and mix.

Add the eggs one at a time, letting each incorporate, and scrape the bowl down.

Drizzle in the vanilla; separately mix the vinegar into the buttermilk.

Mix red food colouring into the batter until it looks properly red.

Sift the cocoa powder in and mix it well before the flour goes anywhere near the bowl.

Add half the dry mixture, then half the wet, then the rest of the dry and the rest of the wet, mixing only until combined so the gluten is not activated.

Divide between the prepared pans, weighing them so they match; it foams as the vinegar and baking soda react.

Steal a little batter from each pan, colour it more strongly and bake it as one cupcake, about 15 minutes, for the crumbs.

Bake at 350F close to 35 minutes, until the edge pulls away from the pan and the centre is springy.

Cool until touchable, tap the pan laterally to break the cake free and turn it out; cool completely.

For the frosting, mix the room temperature butter and the cream cheese a few minutes until creamy and homogenous.

Add the vanilla and a pinch of salt, then the powdered sugar in batches, mixing on low -- beating on high puts in air bubbles that spoil the decorating.

Glue the first layer to the plate with a little frosting and use about half a cup between each layer.

Cover the top and sides, piping the frosting on from a bag and smoothing it with a small knife; chill if it goes wobbly.

Crumble or grate the reserved red cupcake into crumbs.

Pipe a scallop pattern round the top with an 846 tip and press the crumbs onto the base as a skirt, with a few on top.