Preheat the oven to 190 degrees Celsius, 375 Fahrenheit, or 170 degrees fan.
Cut the apricots in half, and remove the pits.
Melt the butter in a pan set over a low heat, then allow it to cool slightly.
Butter an ovenproof dish well, then sprinkle the brown sugar over.
Add the apricots, scattering them evenly over the bottom of the pan.
In a large bow, sift the flour, add the oats, granulated sugar, vanilla extract and melted butter, and use a spatula to mix well.
Spread the topping over the apricots, and bake for 35 minutes or until golden and bubbling hot.
Serve warm or cold with custard or your favourite ice cream.