Heat sugar, cinnamon, blueberries, and 14g butter in a pan until simmering.
Simmer for 4 minutes until blueberries break down and sugar turns golden-brown.
Add peach liqueur and boil for one minute while stirring.
Remove the pan from the heat and set aside.
Rub muesli, flour, brown sugar, and 100g butter together in a bowl until crumbly.
Toast the crumble mixture in a dry frying pan until golden-brown.
Mix honey and mascarpone together until smooth.
Divide filling into two ramekins and top with the toasted crumble.
Serve the ramekins with a spoonful of honeyed mascarpone on the side.