Step 1

Preheat oven to 180°C/160°C fan forced. Grease the base and side of a 1.5L (6 cup) ovenproof dish with butter. Place the dish in a large roasting pan.

Step 2

Place the condensed milk, golden syrup and chopped butter in a saucepan. Cook, stirring constantly, over medium-low heat for 2 minutes or until the butter melts and the mixture darkens slightly. Pour the sauce mixture into the prepared dish. Arrange the apple on top.

Step 3

To make the crumble topping, place the flour and butter in a bowl. Use your fingertips to rub the butter into the flour until the mixture resembles coarse crumbs. Stir in the oats and brown sugar.

Step 4

Place the cake mix, eggs, milk and butter in a bowl. Whisk until just combined. Pour the mixture evenly over the fruit. Smooth the surface. Scatter over the crumble topping.

Step 5

Pour enough boiling water into the roasting pan to reach halfway up the side of the dish. Bake for 50 minutes or until the pudding is firm when lightly touched. Serve with ice-cream.