To make the jam, place the strawberries, date syrup and vanilla extract in a small saucepan. Bring to the boil, then reduce the heat and simmer until thickened to a soft, spreadable consistency. It doesn't need to set like traditional jam. Leave to cool.
Preheat the oven or air fryer to 180°C. Line a small square baking tin with baking parchment or prepare a silicone baking mould.
Mash the bananas until smooth, then stir in the vanilla extract.
Add the oats, ground almonds (if using) and cocoa powder, mixing until well combined.
Fold about 3 Tbsps of the cooled strawberry jam into the mixture. Leave to rest for 5–10 minutes so the oats can absorb some of the moisture.
Spoon the mixture into the prepared tin or mould and spread it out evenly.
Bake in the oven for 20–25 minutes, or until lightly set and firm to the touch.
Alternatively, bake in the air fryer for 15–18 minutes.
Leave to cool in the tin before transferring to a wire rack.
Once completely cool, cut into squares and serve.