Directions:
In a bowl, combine the butter, powdered sugar, egg yolk, and condensed milk until pale in color.
Perfume with lemon zest.
Sieve and incorporate twice as much cornstarch and baking powder.
The mixture will be somewhat sticky.
Let rest in the fridge for 1 hour on plastic wrap.
Weigh a 10 g portion and form a sphere.
Place on a plate lined with parchment paper/silpat/nonstick sheet. Press lightly with a fork.
Bake for 8' to 10' at 170°C or until its base is firm and slightly golden.
Cool completely.
Fill with dulce de leche to taste.
Enjoy!
