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.
Add flour, milk, and heavy cream alternately. Mix until the dough sticks to the whisk, forming clumps.
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. Cool completely before adding toppings