Preheat your oven to 180C/350F.
Cut up your croissants into bite-sized pieces. Place the croissant pieces into a baking pan.
Place all the ingredients for your custard into a bowl and mix well until the mixture is homogenous. Pour the custard over your cut up croissants and let the croissants soak for at least 5 minutes or overnight if you're preparing in advance. [tip: you might need to adjust the amount of custard you need to make, depending on the size of your croissants and the size of your baking pan. Ideally, you would want enough custard to cover 90% of the croissants]
Top with mixed berries and bake for 25-30 minutes or until the top is golden brown and crispy. Dust with icing sugar. Serve with maple syrup and whipped cream