• Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
• In a microwave-safe bowl or using a double boiler, melt the chocolate and butter together. Stir until smooth and set aside to cool slightly.
• In a separate bowl, whisk together brown sugar, granulated sugar, and eggs until well combined. Mix in the vanilla extract.
• Add the chocolate mixture to the sugar and egg mixture. Whisk until well combined.
• Sift in the flour, baking soda, baking powder, and salt. Stir until just combined, being careful not to overmix.
• Using a cookie scoop or a spoon, drop 1.5tbsp rounds of dough onto the prepared baking sheets, spacing them about 2 inches apart. Bake for 9-10 minutes, or until the edges are firm but the centers are still soft. Remove from the oven and use a round cookie cutter to shape the cookies into circles.
• Allow cookies to cool on the baking sheets for 5 minutes before transferring them to wire racks to cool completely.

Filling

• Cream together the butter and peanut butter until smooth. Add in the powdered sugar, vanilla extract, and salt. Beat until smooth and creamy.

Assemble

• Once the cookies are completely cool, take one cookie and spread a generous amount of the peanut butter filling on the flat side. (I use a cookie scoop and press the other cookie on top). Place another cookie on top of the filling, flat side down, to form a sandwich. Continue this process until all cookies are paired and filled.