Process the ground almond and icing sugar in a food processor. Sift the ingredients into a large bowl.
Add 55 g of egg whites to the ground almond and icing sugar mixture. Stir into a thick paste.
Put the other 55 g of egg whites into a clean, grease-free bowl. Whisk the egg whites for a while and add in the 25 g of sugar. Continue to whisk until egg white is foamy.
Mix 125 g of sugar and water together in a small sauce pan. Bring the sugar syrup to a boil, then reduce heat to medium and continue cooking sugar syrup reaches 120C.
Remove sugar syrup from heat and while the mixer is running at the highest speed, slowly pour the syrup into the bowl and continue whisking.
Fold the meringue into the almond mixture in 3 additions (stir gently at the last addition). Add a drop of colouring. Continue folding until the mixture falls off the spatula like lava, forming a thick ribbon (try to be fast and efficient and don’t work the dough for too long).
Fill the prepared piping bag fitted with the round plain tip with the macaron batter.
Pipe the macarons batter onto the lined trays by pressing out 1.5 inch circles about 1 inch apart.
Lightly tap the tray on the table 5-10 times to remove any large bubbles.
Bake the macarons in pre-heated oven on 135C for 13 to 15 minutes.
Remove from the oven and allow to cool completely before removing macarons off the parchment paper.
To make the ganache, mix cream and banana puree. Heat unit boiling. Pour in chocolate and mix well.
Cool the cream and add in the butter.
Fill up a piping bag with the ganache, place a small amount in between 2 macarons then stick them together.