Prepare the Pastry:

1. In the bowl of a food processor, combine the flour, salt and sugar. With the processor running on low, add the butter, a few cubes at a time, and continue processing until you have a coarse, sandy mixture.
2. Add the egg, and pulse 2-3 times to combine. Add the cream and almond extract, and pulse again until the dough starts to come together into a ball. Turn the dough out onto a clean surface lightly dusted with flour, and use your hands to push it all together into a ball. Divide the dough into 12 equal pieces, and roll each one into a ball.
3. Press the dough into eight 4-inch tartlet pans, pushing it evenly over the bottom and up the sides. Transfer to the refrigerator to chill for at least 1 hour.

Blind-Bake the Pastry:

1. Preheat the oven to 375F. Arrange the tart pans on a baking sheet, and prick the bottom of each shell a few times with a fork. Bake for 10-12 minutes, or until the pastry is dry to the touch and a pale golden-brown.
2. Place the tart shells on a wire rack to cool off completely while you prepare the filling.

Prepare the Filling:

1. In a small saucepan set over medium-high heat, combine the whipping cream and milk. Heat up the mixture, stirring constantly, until wisps of steam start to rise from the surface and it's just starting to simmer. Remove from heat immediately.
2. In a medium-sized mixing bowl, whisk together the egg, sugar, flour, and salt. Slowly drizzle in the warm cream,  whisking until well combined.

Assemble and Bake the Tarts:

1. Preheat oven to 350F.
2. Arrange the berries in the cooled shells. Slowly pour in the custard so it fills in the spaces between the berries, dividing evenly between the tarts.
3. Bake in preheated oven for 30 minutes, or until the berries are soft and the custard is set. (It's okay if it's still a little jiggly in the middle.) Transfer to a wire rack to cool off - depending on your preference, you can serve these tarts still slightly warm from the oven, or cool off completely and chill until ready to serve.