Preheat oven to 350 degrees F and line 2 baking sheets with parchment paper.
In a large bowl, cream together butter and powdered sugar using an electric mixer until light and fluffy.
1/2 cup butter , 1 cup powdered sugar
Add egg and vanilla extract and beat to combine.
1 large egg, 1 tsp vanilla extract
Add in flour and sea salt and mix until just combined.
1¼ cup gluten free all purpose flour, 1/2 tsp sea salt
Transfer the dough to a piping bag or a resealable bag with the corner snipped off about 1 inch wide.
Pipe 3-inch long logs on the prepared baking sheets, spacing them about 1 inch apart. The shapes don’t have to be perfect, they’ll set in the oven.
Bake for 10-11 minutes until the centers are set. Turn off the oven and leave the oven door ajar. Leave the cookies to crisp up for 15 minutes. Remove from the oven and use a spatula to transfer to a cooling rack until cooled completely.
Melt chocolate chips in a double boiler or in the microwave at 30 second increments until smooth.
3/4 cup semisweet chocolate chips
Add a spoonful of melted chocolate on to one cookie, spread it out with the back of the spoon, then sandwich the chocolate with another cookie. Repeat with the rest of the cookies. Set aside to set.