Preheat & Prep: Preheat your oven to 375°F (190°C) and line two large rimmed baking sheets with parchment paper. Place unwrapped chocolate truffles in the refrigerator or freezer for 15 minutes so they maintain their round shape during assembly.

Make Dough: In a stand mixer fitted with paddle attachment or large mixing bowl, beat softened butter, creamy peanut butter, brown sugar, and granulated sugar on medium speed for 2 minutes until light and creamy. Beat in the egg and vanilla extract until fluffy.

Combine Dry Ingredients: Whisk flour, baking soda, and salt in a separate bowl. Gradually add to the wet peanut butter mixture on low speed just until dough comes together. Do not overmix.

Roll & Indent: Scoop 1-tablespoon portions of dough, roll into smooth balls, and roll through the extra granulated sugar. Place 2 inches apart on prepared sheets. Using the round back of a 1-tablespoon measuring spoon, gently press a small indentation into the center of each dough ball.

Bake: Bake at 375°F (190°C) for 8 to 10 minutes until edges are set and light golden, while centers remain tender and soft.

Insert Truffle Body: Remove from oven. Allow cookies to cool on the baking sheet for exactly 4 to 5 minutes until warm but not piping hot. Gently press a chilled chocolate truffle into the center indentation of each cookie. (The residual warmth will anchor the truffle without melting it into a puddle).

Pipe Spider Legs & Attach Eyes: Place melted chocolate into a small piping bag or zip-top bag with a tiny corner snipped. Pipe 8 curved spider legs (four on each side) extending from the truffle body onto the cookie. Dab two tiny specks of melted chocolate onto the front of the truffle and affix the candy eyeballs. Let cookies set completely for 20 minutes before serving.