Cream together butter, eggs, sugar, and vanilla extract in the bowl of a stand mixer.
Next, add salt, baking powder, and baking soda. Mix until well combined.
Alternate adding flour, milk, and heavy cream. Mix until the dough sticks to the whisk, forming a clump.
Cover the bowl with a tight layer of plastic wrap. Refrigerate for 1 hour.
Preheat over to 350℉—line 2 baking sheets with parchment paper and set aside.
Evenly sprinkle a layer of four over a clean, flat surface. Roll half the dough out until it is about ½ an inch thick. Cut the dough into the desired shape and place it on the prepared baking sheet, leaving 2 inches between each cookie. (This dough is very soft, so I recommend using shapes that don't have a lot of detail).
Bake the cookies for 8-10 mins. The best way to tell if these cookies are done is to carefully lift the corner of one with a spatula to see if the bottoms are slightly golden brown. If you start to see a golden brown color on the outside/top of the cookies they will not be as soft.
Immediately remove the cookies from the baking sheet and place them on a cooling rack.