Ingredients:
For the cookie dough:
1/2 cup unsalted butter (1/5 cup is not a standard measurement)
2 tsp granulated sugar
1 egg yolk
1 cup all-purpose flour
1 dash salt
5 tbsp water
For the filling:
3/4 cup granulated sugar
1/4 cup flour
1 cup milk
1 cup unsalted butter
1 tsp vanilla extract
1 dash salt