Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.

In a large bowl, beat the butter and sugar until light and fluffy. Add the egg and vanilla, mixing until smooth. Gradually add the dry ingredients and milk until combined.

Drop tablespoon-sized dollops of dough onto the baking sheet, spacing them 2 inches apart. Bake for 8-10 minutes until the edges are lightly golden. Let them cool.

For the filling, whisk together the heavy cream, powdered sugar, and vanilla. Prepare the pudding mix with milk, then fold it into the whipped cream mixture.

To assemble, sandwich the filling between two cookies.

For the ganache, melt the chocolate chips with heavy cream over low heat. Drizzle or dip the tops of the cookies in the ganache.