Add the mascarpone to the bowl of a large stand mixer fitted with the whisk attachment. Slowly add the heavy cream while whipping over medium speed until it becomes the consistency of a thick whipped cream.

In a medium mixing bowl, whisk together the eggs and egg yolks, milk, espresso, sugar, and vanilla extract until the eggs fall off the whisk in ribbons.

Heat a large non-stick sauté pan or griddle pan over medium heat, add 2 tablespoons (28g) of butter and allow to melt. One at a time, dunk the slices of brioche in the custard mixture, so the egg mixture is absorbed and both sides are soaked but the bread still holds it’s shape.

Remove the slices to a plate, then repeat with the remaining butter and bread until all are cooked. Divide the slices of toast among plates. Add the mascarpone whipped cream to a piping bag or plastic bag with the corner cut off and pipe the cream over the top of the French toast. Add cocoa powder to a fine mesh strainer and shake gently to coat the top with the powder. Serve immediately.