1 cup very fine wholemeal flour
1 ounce caster sugar
1/4 cup margarine
1/4 cup vegetable shortening
2 tablespoons cold water, divided Filling:
3/4 cup margarine
1/2 cup silken tofu
3/4 cup superfine/caster sugar
2 teaspoons vanilla extract
3/4 cup brown rice flour
2 teaspoons baking powder
splash nondairy milk, as needed
5 tablespoons seedless raspberry jam, stirred
3 ounces desiccated coconut
1. Preheat the oven to 425 degrees Fahrenheit, and grease a pie pan. For crust, sift flour into a mixing bowl and stir in the sugar. Add the margarine and vegetable shortening in small (teaspoon sized) lumps and gently rub into the flour/sugar mixture until it resembles bread crumbs. Add the water a small amount at a time, and mix until the dough starts to stick together in a ball.
2. Crush the dough ball twice with the palm of your hand on the work surface, then sandwich between 2 sheets of plastic wrap. Roll out the dough until it's roughly 1/10" thick. The plastic wrap will stretch a little while you roll, and will prevent it from falling apart or sticking to the work surface.
3. When it is the correct dimensions for the pie pan, remove 1 of the sheets of plastic wrap, and press pastry side down into prepared pie pan. Remove the top layer of plastic wrap and patch any gaps in your pie shell as necessary. Poke some holes in the bottom with a fork and bake for 20 minutes. Leave to cool while preparing the filling. Turn oven to 375 degrees F.
4. For filling, blend the margarine and tofu together and add to mixing bowl. Beat in the sugar and vanilla extract until the mixture is light and creamy in color. Sift in the rice flour and baking powder and fold in until the mixture is nicely combined. Add the splash nondairy milk if the mixture is too dry. It should be like a thick cake batter.
5. Put the raspberry jam into prepared pie crust, and spread evenly with the back of a spoon. Pour in the rice flour filling mixture and even out the top if necessary. Sprinkle on the coconut and bake for 45-50 minutes, until the filling no longer wobbles! Leave to cool for 10-15 minutes before serving.
It is delicious both hot and cold. I have no clue where this originated, but I like to think that it was one of Thomas Gainsborough’s favorite tarts and was named after him. I actually work in Gainsborough’s sisters house and I can just imagine this deliciously sweet dessert being served up there! It's a recipe that my Grandmother always used to make to go with afternoon tea and I hope you enjoy it as much as I do. For more details, rambles and recipes you can view the full blog post here: http://veganbritannia.blogspot.com/2011/08/goodbye-mister-potter.html 
Source of recipe: I adapted my great grandmother's recipe.