Step 1

In a large mixing bowl, cream butter and 1 cup of sugar for 4 minutes, until light and fluffy.

Step 2

Add egg and vanilla and mix for 1 minute.

Step 3

Stir in flour, baking soda, and salt.

Step 4

Let mixture chill in the refrigerator for 10-15 minutes.

Step 5

Combine 1/2 cup of sugar and 2 teaspoons of cinnamon in a shallow bowl.

Step 6

Roll into 16 - 24 balls, depending on the desired size of cookies.

Step 7

Drop into cinnamon sugar mixture and coat well.

Step 8

Place on parchment or Silpat covered baking sheet.

Step 9

Bake at 350 degrees for 9 - 11 minutes or until lightly golden brown on edges but still soft.

Step 10

May sprinkle with remaining cinnamon-sugar as soon as removed from the oven.

Step 11

To make filling: melt butter in small saucepan. Remove from heat and immediately stir in the can of dulce de leche. Spread dulce de leche on the bottom of cookie and top with another cookie.

Step 12

*Recipe adapted from America's Test Kitchen Cookie Cookbook