To make the crust, put the flour, sugar, and salt in a large bowl. Add the cubed butter.
With a pastry blender, cut the butter into the flour until it is crumbly and the largest pieces are pea sized.
Add the water and vinegar and mix with your hands until you have a shaggy dough.
Transfer to a clean surface and dust with flour. Cut into four pieces, wrap each piece in plastic and chill for 30 minutes.
To make the filling, put the berries, sugar, tea, and lemon juice in a medium saucepan. Bring to a boil and reduce until the berries are broken down and it coats the back of a spoon. Let cool while you roll out the pie dough.
Remove the pie crust from the fridge and roll each piece into a rectangle about 1/4 inch thick.
Using a sharp knife or pastry roller, cut the pie dough into 1x2 inch rectangles. You’ll need two pieces for each mini tart.
Spoon a teaspoon or two of filling onto half of the cutouts and top with the other half. Press the edges together.
Using a sharp knife, cut a tiny x in the center of each pie and transfer to a parchment lined baking sheet.
Beat the egg with the milk and brush the pies with the egg wash.
Bake for 10-15 minutes, until crust is golden brown and filling is bubbly.
To make the icing, put a fine mesh sieve over a bowl and press the raspberries into it, catching the juice below. Once all of the raspberries are pressed, add powdered sugar a tablespoon at a time and whisk until you’ve reached the desired consistency. If you need more liquid, you can add a bit of water or milk. Add a pinch of salt.
When the pies come out of the oven, let cool before coating with the icing.