In a separate bowl or mixer add flour, powdered sugar, salt, indi chocolate cacao nibs and blend, then add butter; mix until mixture resembles coarse crumbs.
Add yolk mixture until mixture forms a ball. Shape into a disk and cover with plastic wrap. Refrigerate for at least 30 minutes.
Unwrap the dough and spread it out into a disk and transfer to a 9 inch tart pan.
Press into the bottom and to the sides pulling the dough up the sides.
Bake for 30-35 minutes or until the edges are golden. Remove the foil and weights.
Directions for Dulce de Leche filling:
Heat dulce de Leche for a few seconds over a double boiler and stir
Spoon dulce de leche into tart shell, spreading evenly
Heat 1/2 cup cream in a small saucepan until bubbles appear around the edge.
Remove the cream from the heat and add chunks of indi chocolate to start melting it. Whisk until smooth.
Pour chocolate mixture over dulce de leche; spread with a spatula.