Preheat oven to 375°F (190°C). Grease a mini muffin tin.
In a large bowl, cream together the butter, granulated sugar, and brown sugar until light and fluffy. Beat in the eggs one at a time, then stir in the vanilla extract.
In a separate bowl, whisk together the flour, baking soda, and salt. Gradually add to the wet ingredients, mixing until just combined.
Roll the dough into small balls and press into the bottom and up the sides of each mini muffin cup.
Bake for 10-12 minutes, or until golden brown. Let cool slightly before filling with dulce de leche.
Fill each cookie cup with a spoonful of dulce de leche. Serve and enjoy!
Notes
These cookie cups are best served fresh. Store leftovers in an airtight container.