Step 1

Preheat the oven to 375ºF. Spray a mini muffin pan with nonstick spray.

Step 2

Add flour, powdered sugar and salt to a food processor and process to blend. Add 1/2 cup cold butter and pulse until the mixture resembles coarse meal. Then add cold water and process just until the dough starts to stick together. If the dough is still dry, add more water by the teaspoon.

Step 3

Scoop about a tablespoon of dough into the cups of a mini muffin pan and press onto bottom and partially up sides. The dough will fill anywhere from 18-24 mini muffin cups.

Step 4

Bake until golden brown, about 15 minutes. Remove from oven and cool in pan for 5 minutes. Use a knife to pop out the mini tart shells. Cool completely on a wire rack.

Step 5

Put milk and vanilla bean paste in a medium saucepan and bring to a boil over medium-heat.

Step 6

In a separate bowl, whisk the egg yolks and granulated sugar until light and fluffy. Add in the cornstarch and whisk until no lumps remain.

Step 7

Next whisk in 1/4 cup of the hot milk mixture into the egg mixture until incorporated. Whisk in the remaining hot milk mixture, reserving the empty saucepan.

Step 8

Pour the mixture back into the saucepan. Cook over medium-high heat, whisking constantly, until thickened and slowly boiling. Remove from the heat and stir in the butter.

Step 9

Spoon custard into the cooled crust cups and let sit at room temperature for about 20 minutes. Top with berries and refrigerate until ready to serve.