Preheat the oven to 180°C fan.
Melt the butter in your 25cm Halo LaserDefense pan over a medium heat. Add the diced apples, cinnamon and brown sugar and cook for 5-7 minutes, stirring occasionally, until softened and lightly caramelised. Remove from the heat.
Whisk together the egg, honey, olive oil, milk and vanilla in a mixing bowl. Add the flour, baking powder, cinnamon and salt, and gently fold until combined.
Spoon the batter evenly over the apples, spreading it gently to cover them.
Sprinkle the brown sugar evenly over the batter. Slowly pour the boiling water over the back of a spoon onto the surface. Do not stir!
Carefully transfer the pan to the oven and bake for 18-20 minutes, until the sponge is risen and golden, with a bubbling sauce underneath.
Leave to stand for 5 minutes (optional: sprinkle with flaky salt) then serve straight from the pan with ice cream.
