Preheat the oven to 175C/350F.
Grease/Spray a 20cm (8 inch) spring form cake tin or pie dish (a 22cm/9inch can also be used)
Mix the dry ingredients in a blender.
In a separate small bowl, whisk together the wet ingredients.
Pour the wet ingredients into the dry, and blend until combined. A dough ball will form.
Roll the doughnut between 2 sheets of baking paper and trace a plate/tin bigger than tart tin.
Gently place circle in tin. Use excess dough to ensure an even edge.
Alternatively, spread dough evenly in tin and up the edges by hand
Bake for 15 minutes. Cool completely.
If using a spring form tin, remove the crust and place on a serving tray. This may be more difficult if using a pie tin and you may choose to construct the pie and serve from the tin.