Prepare the oranges by cutting off the top and bottom, then carefully removing the peel and white pith.

Slice the oranges into small chunks and remove any seeds or excess pith.

Place the orange pieces in a bowl and mix with cornstarch, honey, and lemon juice.

Transfer the mixture to a baking dish and let it sit at room temperature for 1 hour.

Preheat the oven to 400°F (200°C).

In a large bowl, whisk together almond flour, cornstarch, oats, cardamom, salt, and cinnamon.

In another bowl, mix almond butter, honey, vanilla, and mashed banana until smooth.

Fold the wet mixture into the dry ingredients to form a crumble texture.

Spoon the crumble evenly over the citrus filling.

Cover loosely with foil and bake for 30 minutes.

Remove the foil and bake for another 20 minutes until golden and bubbling.

Let the Citrus Crumble cool to room temperature before serving.