Prepare the Cookies: Preheat your oven to 350°F (175°C). In a large mixing bowl, beat together the softened butter and sugar until the mixture is creamy and smooth. Add in the eggs and vanilla extract, beating until well combined.

Mix the Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Gradually incorporate this dry mixture into the wet ingredients until a dough forms.

Shape the Cookies: Use your hands to shape the dough into small balls and place them on a baking sheet. Slightly flatten each ball with the palm of your hand. Bake for 10-12 minutes or until the edges are golden. Once baked, let them cool completely.

Create the Cream Filling: In a saucepan, combine the milk, sugar, cornstarch, and salt. Cook over medium heat, stirring constantly until it thickens. In a small bowl, beat the egg yolks, then add a spoonful of the hot mixture to temper them. Return the yolk mixture to the saucepan and cook for an additional 2 minutes before stirring in the vanilla extract. Allow it to cool.

Prepare the Chocolate Topping: In a microwave-safe bowl, combine semi-sweet chocolate chips and heavy cream. Microwave in 30-second intervals, stirring in between, until smooth and glossy.

Assemble the Cookie Bites: Place a spoonful of the cream filling on one cookie and top it with another cookie. Dip the top of the sandwich into the chocolate topping. Allow the chocolate to set before serving.