Preheat your oven to 350°F (175°C).

In a mixing bowl, cream the softened butter and granulated sugar together until light and fluffy, about 3-4 minutes.

Add the egg and vanilla extract; mix well.

In another bowl, whisk together the flour, baking powder, and salt.

Gradually add the dry mixture to the wet mixture, mixing just until combined.

Using a spoon or cookie scoop, drop small amounts of dough (about a tablespoon) onto a baking sheet lined with parchment paper, spacing them about 2 inches apart.

Place the baking sheets in your preheated oven and bake for 12-15 minutes, or until the edges are lightly golden.

Allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

While the cookies cool, melt the chocolate chips with heavy cream in a microwave-safe bowl in 20-second intervals, stirring in between until smooth.

Once the cookies are cool, spread a generous amount of chocolate filling on the flat side of one cookie and top with another cookie, pressing gently together.

Enjoy fresh, or store in an airtight container for later.