First make the chocolate ganache, place the cream and ground coffee in a saucepan and bring them to the boil. Remove the pan from the heat and leave to infuse for 15 minutes.
Pour the cream mixture through a muslin or a fine sieve so that all of the coffee grounds are removed.
Return the cream to the heat and bring to the boil, pour it onto the chocolate and stir until combined and all of the chocolate has melted.
Leave the chocolate somewhere to cool, you don't want it to set completely as it needs to be soft enough to pipe. If the chocolate does set too much, it can be melted in the microwave in short bursts and stirred to soften.
Next make the macaron shells, preheat the oven to 170 degrees and line two baking trays with baking parchment. Draw two 20cm circles on the reverse of the baking parchment to help with the piping. Also draw 20 smaller circles on another piece of baking parchment, the standard size is usually a diameter of 4cm.
Add the water and sugar to a pan and stir over a medium heat until the sugar has dissolved and the syrup reaches 121 degrees.
Put 75g of the egg whites into a stand mixer and whisk them on a medium speed until frothy.
Pour the syrup in a slow steady stream into the egg whites as they are being whipped on a high speed. Keep whipping until the meringue forms a stiff peak and is barely warm to the touch, about 5mins.
Grind the ground almonds and icing sugar together in a food processor and then sift them into a clean bowl. Add the remaining egg whites to this mix and beat, until it forms a paste.
Add a third of the meringue to the almond paste and beat it in thoroughly. Fold through the remaining meringue, ensure the ingredients are mixed thoroughly, but gently. At this point if you want to make a mixture of white and cocoa coloured macarons, reserve some of the mixture in a separate bowl (around 5-6 tablespoons). Add the cocoa powder to the remaining mixture and fold until it is fully mixed in.
Put the macaron mix into a piping bag and pipe out two circles working in a spiral from the centre, then pipe out the small macarons, using the remaining chocolate and plain mixture.
Tap the bottom of the tray for the smaller macarons ONLY. Place the large macarons in the oven for 15mins. Turn the trays halfway through cooking to ensure an even bake.
Then cook the smaller macarons for 10mins. Let the cooked macarons cool completely before trying to remove them from the tray.
Next make the mascarpone cream, add all of the ingredients to a bowl and whisk until combined. Return the mascarpone cream to the fridge.
Take a large macaron and put in on a plate or cake card and pipe alternating blobs of coffee ganache and mascarpone cream around the edge of the macaron. Then pipe alternating rings of mascarpone cream and coffee ganache until you have covered the whole macaron.
Sandwich a plain macaron on the top and add any decorations of your choice.
With the smaller macarons, pipe a ring of the coffee ganache around the edge of the white macaron and pipe a blob of mascarpone cream in the middle. For the cocoa macarons pipe a ring of the mascarpone cream and a blob of the coffee ganache in the middle. Sandwich the same coloured macaron on top.
Place the smaller macarons in an airtight container for at least an hour, the larger one will be fine in the fridge on a plate, but if you can wait, they'll be much better the next day. They should last for 2-3 days in the fridge.