01 - Line a cookie sheet with wax paper. Place peanut butter in a microwave-safe bowl and heat for 30 seconds until slightly softened. Add sifted powdered sugar and ground cinnamon; stir until fully incorporated.
02 - Spoon 1/2 tablespoon portions of the peanut butter mixture onto the prepared cookie sheet to make 20 even mounds. Freeze for 1 hour to firm.
03 - In a medium bowl, sift together flour, Dutch process cocoa powder, baking soda, and salt. Set aside.
04 - In a large bowl, whisk together melted unsalted butter, brown sugar, granulated sugar, vanilla extract, and eggs until smooth and combined.
05 - Add dry ingredients to the wet mixture and mix gently using a rubber spatula until a soft dough forms. Fold in semi-sweet chocolate chips until evenly distributed.
06 - Allow the cookie dough to rest at room temperature for 10 minutes to minimize spreading during baking.
07 - Preheat oven to 350°F (177°C). Line two baking sheets with parchment paper.
08 - Scoop 2 tablespoon-sized (1 oz) portions of dough. Press your thumb into the center to create an indentation. Place a frozen peanut butter filling mound in the center, then fold dough around to fully encase the filling.
09 - Arrange 6 dough balls per baking sheet, spaced evenly. Bake in the preheated oven for 13 to 15 minutes, until edges are set and centers are soft.
10 - Let baked cookies rest on the hot baking sheet for 5 minutes, then transfer to a wire rack to cool completely before serving.