1.In a small oven-proof frying pan, melt butter with sugars and water. Stir until sugar dissolves; bring to boil. Add apples; reduce heat, simmer, turning occasionally, about 10 minutes or until tender.
2.In a food processor, process flour, icing sugar, zest and butter until mixture is crumbly. Add egg yolk and water; process until ingredients just come together. Wrap in plastic wrap and refrigerate 40 minutes.
3.Preheat oven to 220°C (200°C fan-forced).
4.Roll pastry between baking paper until slightly larger then the circumference of the frying pan. Remove paper, turn pastry onto apples. Remove remaining paper; tuck pastry between apples and side of frying pan.