Line 3, 8" (or 4, 6") pans with parchment paper and grease the sides.
In a bowl sift the flour, salt and baking soda. Mix to combine and set a side.
Place the sugars in a bowl of a standing mixer and pour in the melted butter.
Mix on low with the paddle attachment.
Add the egg, egg yolk, milk and vanilla.
Sprinkle in the flour mixture and the chocolate chips and stir just to combine.
Divide the cookie dough into the prepared pans. Chill for few hours or over night.
When ready to bake, place pans in the middle rack and bake for 25 minutes in 340F.
Remove from the oven and allow to cool completely before removing from pans.
Place the chocolate chips in a microwave prof bowl pour the heavy cream and heat in the microwave for 45 seconds.
Stir until the chocolate had completely melted.
Place a layer of cookie on a serving plate or in an 8" ring, spread 1 cup of your choice of butter cream. Repeat with the remaining cookie layers.
Using a spoon, drizzle the edge of the top layer with the melted chocolate. Decorate with sprinkles.