Keep the thawed puff pastry at 40°F until you start, then work for 6 to 8 minutes so the butter stays firm. Cut the sheet into 24 narrow strips about 1/2 inch wide and cut 4 ounces of sharp cheddar into 24 slim batons. Pat all 24 fully cooked chicken cocktail sausages dry, then line each sausage beside one cheddar baton. Use clean straight cuts and avoid stretching the pastry. It should feel cool and bend without sticking. Warm pastry smears if you miss this window. For these Halloween Cocktail Party Appetizers, the strips should look slightly uneven rather than ruler straight. You'll see clear pastry layers at the cut edges. Keep the butter cold because distinct layers create the flaky lift.

Place one sharp cheddar baton along each of the 24 chicken cocktail sausages, then wind one puff pastry strip around each sausage in loose crossing bands. Leave two small gaps near one end for the eyes. Whisk the large egg with 1 tablespoon water for 30 seconds and brush a thin coat over the pastry, then press two black sesame seeds into each eye gap. Finish all 24 in 10 to 12 minutes and chill them at 40°F for 10 minutes. Don't wrap tightly because the pastry needs room to expand. These Halloween Cocktail Party Appetizers should look irregular and a little silly before baking. The pastry will feel firm after chilling. Chill at 40°F because firm butter separates into crisp layers in the oven.

Bake the chilled tray at 400°F for 14 to 17 minutes and rotate it once at minute 9 so the pastry colors evenly. Keep the 24 bites spaced apart and don't move them before the pastry sets. The bands should puff into crisp ridges while small beads of sharp cheddar bubble at a few seams. Check one center with an instant read thermometer and look for 165°F because the chicken sausages should be fully hot. Go past 18 minutes and the thin pastry tails can dry out. (I tested 425°F first. The strips darkened too fast, so 400°F worked better.) These Halloween Cocktail Party Appetizers are ready when the pastry is deep gold and faintly sizzling. Bake at 400°F because steady high heat lifts the pastry before the cheese leaks.

Keep the whole milk Greek yogurt near 40°F and whisk it with Dijon mustard, pure maple syrup, apple cider vinegar, smoked paprika and kosher salt for 45 to 60 seconds. Start in the center and widen the circles until the dip turns smooth and pale gold. Let the baked bites rest for exactly 5 minutes, then move all 24 to a serving plate and set the dip beside them. Don't plate them straight from the oven because trapped steam can soften the bottoms. The final Halloween Cocktail Party Appetizers should crackle lightly when you press a pastry edge and the dip should cling to a bite without running. Rest 5 minutes because released steam keeps the pastry crisp.