Chocolate Chip Vanilla Filling Cookie Sandwiches

Preheat your oven to 325°F (165°C) and line the cookie sheets with parchment paper.

Mix together the flour, baking soda, and salt in a bowl.

In another bowl, cream together the melted butter, brown sugar, and white sugar until well blended. Beat in the vanilla, egg, and egg yolk until light and creamy.

Gradually add the flour mixture to the butter mixture and stir to combine. Fold in the chocolate chips.

Drop cookie dough onto the prepared cookie sheets with a cookie scoop or spoon.

Bake for 15-17 minutes in the preheated oven, or until the edges are lightly browned. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.

While the cookies are cooling, make the filling. Beat together the butter and shortening together until fluffy. Gradually add in the powdered sugar and mix until blended.

Stir in the salt, vanilla extract, and milk and beat until fluffy.

Once the cookies are completely cooled, spread about 2 tablespoons of filling onto one cookie and sandwich with another. Repeat until all the cookies are used.