Preheat the oven to 180℃.

To make the almond cream, add the butter, castor sugar, and almond extract to a small mixing bowl. Mix together until smooth. Add the eggs and mix again. Add the dark rum, almond flour, corn flour, salt, and baking powder, and stir together until smooth.

Slit the croissants and add two tablespoons of the cream into each croissant, spreading a teaspoon on top. Repeat until all croissants are prepared, setting aside any leftover mixture.

To make the egg custard, add the eggs, sugar, and vanilla to a mixing bowl and whisk until combined. Add the milk and cream, and whisk together until smooth.

In an 8x8 inch baking dish, arrange the almond cream stuffed croissants snugly. Dollop extra almond cream into the gaps between the croissants.

Pour the egg custard over the croissants and allow them to soak for a minimum of 15 minutes.

Generously sprinkle flaked almonds and granulated sugar over the top.

Bake for 35-40 minutes until the top is golden and the center is not wobbling.