In a bowl, whisk together the flour and salt. Set aside.

In the bowl of stand mixer fitted with a paddle attachment, beat the butter and sugars on medium speed about 4 minutes until light and fluffy. Scrape down the side of the bowl and add the egg yolks and vanilla. Beat to combine.

Turn the mixer to low and add the dry ingredients, mixing until just combined. Stir in the chopped chocolate chips.

Preheat your oven to 360 degrees F.

With a paper towel, grease your molds with shortening.

You'll need about 3-4 tablespoons of dough per shot mold. Begin by flattening about a tablespoon of dough to a 1/4-inch thickness and adding it to the bottom of the mold. Flatten another piece of cookie dough to 1/4-inch thickness and add that to the side of the mold. Continue adding dough until the interior of the mold is evenly covered with a 1/4-inch thickness of cookie dough. Repeat with all molds.

Use a knife to cut off any dough that's above the top of the mold. Add the mold inserts and place the filled molds in the freezer for about 10 minutes.

Take the cookie shot molds out of the freezer and bake for 20-22 minutes or until the tops begin to brown. Remove them from the oven and allow to completely cool on a wire rack.

Remove the cookie shots from the molds.

In a microwave-safe bowl, microwave the 1 cup of milk chocolate chips at 30-second intervals to melt. Using a butter knife or small offset spatula, coat the interior of the cookie shot with chocolate.

Optional: Dip the rim of the cookie shot into the melted chocolate and then into sprinkles or nuts.

Allow the chocolate to set before serving the cookie shots with a pitcher of cold milk.