Preheat the oven to 180c.
For the crumble – between your fingers, combine the butter with the flour, add in the sugar and the oats and stir to blend together keeping the mix crumbly. Add in the cinnamon.
To make the base, place the flour, baking powder and butter into a food processor and pulse until crumbed, add in the sugar and pulse again.
Combine the egg with the water and add this to the mixture pulsing again until the pastry just comes together.
Tip the pastry into a greased 23inch baking tin and press in the pastry so that it sits about 3-4 mm thick.
Spread over the peach conserve and set aside.
Blend together the yoghurt, sour cream and honey with the eggs until smooth. Pour this over the peach jam and top with the crumble.
Bake for 40 minutes until set to touch and golden brown. If you need to brown the top, place it under the grill for 3-4 minutes.