Let’s embark on this baking adventure together, step by step. Remember, the key to great baking is patience and love, just like Mama Lou taught me.

1. Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper.
2. In a large bowl, cream together 1 cup of softened butter, granulated sugar, and brown sugar until light and fluffy, about 3-4 minutes.
3. Beat in the eggs one at a time, then stir in 2 teaspoons of vanilla extract.
4. In a separate bowl, whisk together all-purpose flour, cocoa powder, baking soda, and salt.
5. Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Stir in the chocolate chips.
6. Drop tablespoon-sized portions of dough onto the prepared baking sheets, spacing them about 2 inches apart.
7. Bake in the preheated oven for 10-12 minutes, or until the edges are set. Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack.
8. While the cookies cool, prepare the filling. In a medium bowl, cream together 1/2 cup softened butter and 3/4 cup brown sugar until smooth.
9. Mix in the milk and 1 teaspoon vanilla extract. Gradually add the flour and salt, mixing until well combined. Stir in mini chocolate chips.
10. Once the cookies are completely cool, spread a generous amount of filling on the flat side of one cookie, then top with another cookie to create a sandwich.