When can you start? formula minoxidil alfa estradiol To make the crumb crust, melt 60g butter in a small saucepan and add 3 tablespoons of double cream. Crush 275g open-textured ginger biscuits in a food processor, then stir into the melted butter mixture. When all the crumbs are moist, set about 3 tablespoons of them aside, then tip the rest into a 20cm loose-bottomed cake tin and smooth them gently, but avoid compacting them. You want a loose, crumbly crust.