In a large bowl, cream together softened butter and Greek yogurt until smooth and light—about 2–3 minutes with an electric mixer. You’ll see it turn pale; that’s your cue.

Stir in sugar, cocoa powder, and vanilla. Mix just until no dry streaks remain. It’ll look thick—like brownie batter but slightly drier.

In a separate bowl, whisk flour and salt. Gradually fold the dry mix into the chocolate batter until combined; avoid overmixing or you’ll get chewy bites, and we want tender.

Gently fold mini chocolate chips into the batter with a silicone spatula, saving a handful for topping.

Use a small cookie scoop or tablespoon to portion out truffle-sized mounds onto a parchment-lined baking sheet. Press down lightly so each is about 1 inch thick. Sprinkle tops with reserved chips.

Pop the baking sheet into the fridge for at least 30 minutes—this firms them up so the decorations stick.

Melt white chocolate chips or candy melts according to package instructions. Drizzle or pipe little ghost faces, tiny pumpkin grins, or random spooky shapes. Let set, then transfer treats to a festive platter.