Preheat the oven or air fryer to 180°C.
Thinly slice the croissants.
In a bowl, whisk together the custard, cinnamon and ground almonds.
Briefly dip some of the croissant slices into the custard mixture, then arrange them in two ramekins or silicone baking dishes to cover the bases.
Scatter over some of the cherries and a few flaked almonds.
Repeat the layers with more soaked croissant slices and cherries.
Finish with a layer of croissant slices and pour over any remaining custard mixture.
Bake in the oven for 10–15 minutes, or in the air fryer for 12–15 minutes, until the custard has set and the top is lightly golden.
Scatter the remaining flaked almonds over the puddings during the last 3 minutes of cooking so they become lightly toasted without burning.
Leave to cool for a few minutes before serving.
Serve warm with vanilla custard or a scoop of vanilla ice cream. Alternatively, chill and serve cold with extra custard.