Cut the butter into cubes and leave at room temperature to soften.
Fit the K beater to the machine.
Add Ingredients 1 (butter, almonds, sugar, flour, eggs) into the Mixer bowl.
Attach the Mixer bowl to the machine and fit the splash guard.
Mix on speed Max for 1 minute.
Scrape down the bowl.
Mix on speed Max for 1 minute or until light and fluffy.
Add Ingredients 2 (water, sugar, rum, almond extract) into the saucepan.
Heat over a medium high heat until boiling.
Stir until thickened.
Pre heat the oven to 180ºC.
Place Ingredients 3 (croissants) onto the cutting board.
Cut the crossaints lengthways without slicing all the way through.
Brush half the syrup from the saucepan inside each croissant.
Spread half the almond paste from the Mixer bowl evenly into each croissant.
Brush the rest of the syrup on top of each croissant.
Spread the rest of the almond paste on top of each croissant.
Sprinkle the croissants with the first item of Ingredients 4 (flaked almonds).
Transfer the croissants from the cutting board onto the baking tray.
Bake for 10 minutes at 180ºC.
Dust with the last item of Ingredients 4 (icing sugar).