Make the Brownies

Preheat your oven to 350°F / 180°C (160° fan-assisted) and line an 8-inch square pan with parchment paper.

Put the butter and chopped chocolate in a heatproof bowl and melt in the microwave in 30-second bursts, stirring in between, until totally melted. Set aside.

In a large bowl, combine the sugar and eggs and whisk until thick and custard-like. This should take about 30 seconds of vigorous whisking by hand. You can use an electric mixer if you prefer, but it's not necessary.

Pour the melted chocolate mixture into the egg/sugar mixture, add the vanilla and gently whisk everything together until fully incorporated.

Dissolve the espresso powder in a splash of hot water and mix until smooth. Then pour into the brownie batter and stir it in.

Sift the flour and salt into the bowl and use a spoon or spatula to fold everything together until there are no more visible lumps of flour.

Pour the brownie batter into the prepared pan and bake for 25-30 minutes. When they are done, the top of the brownies will be dry and shiny, and when you test the middle of the brownies with a skewer, it will come out slightly chocolatey. If it is caked in a thick layer of raw batter, the brownies need longer. Baking time can vary depending on your oven, so look out for the physical signs that they are ready.

Let the brownies cool completely in the pan, then transfer to the fridge until ready to assemble.

Make the Mascarpone Cream

Add the mascarpone, powdered sugar, amaretto, and vanilla to a bowl and mix together until it is smoothly combined with no lumps.If you don't want to add the amaretto, you can substitute it for 1/2 tsp almond extract, or just leave it out entirely.

In a separate bowl, whip up the cream on medium speed just until stiff peaks form. Don't overwhip it.

Fold the whipped cream into the mascarpone mixture until everything is combined.

Assemble the Tiramisu Brownies

Remove the brownies from the baking pan and peel back the parchment paper from the sides.

There are two ways to decorate these brownies:For a piped finish like in my pictures, transfer the mascarpone cream to a piping bag with a round piping tip fitted and squeeze small blobs all over the top. For a straight finish, you can just spread the mascarpone cream all over the top of the brownies in an even layer. Use a spatula to either smooth it out flat or create some texture on the top of the cream.

Put a little cocoa powder into a small sieve and dust the top of the tiramisu brownies generously with cocoa powder.

Slice the brownies into 16 equal pieces and enjoy.