Melt the unsalted sweet cream butter over medium heat, about 5 on a 10 dial, and keep it moving with slow circular swirls for 6 to 8 minutes. Scrape the milk solids from the bottom every 30 seconds so they brown evenly instead of sticking. Once the foam thins, take it off the heat and cool it for 15 minutes until it reaches about 95°F. You'll smell toasted hazelnuts and see amber flecks suspended through the butter when it's right. Watch closely. Go 30 seconds too far and those milk solids can turn bitter. (I once pushed a batch past deep amber. The whole dough tasted scorched.) Cool to 95°F before mixing because hotter butter can partially cook the egg.

Whisk the 95°F browned butter with the dark brown sugar and granulated cane sugar for 45 seconds, then add the large egg, large egg yolk and pure vanilla extract. Whisk another 30 seconds until the mixture looks thick and glossy. Fold in the unbleached all-purpose flour, baking soda and fine sea salt with a J shaped motion for 8 to 10 turns. The base for Browned Butter Halloween Candy Cookies should lose its dry flour streaks but still look soft and slightly tacky. Stop there. Mix for another minute and gluten starts tightening the dough, which can make the baked centers tougher. The last pale patches should disappear after only a few folds. Fold only until the flour disappears because extra mixing develops too much gluten.

Fold in the M&M's Ghoul's Mix milk chocolate candies, chopped Reese's Miniatures milk chocolate peanut butter cups and semisweet chocolate chips with 8 gentle turns. Reserve about 2 tablespoons of the colorful candies for the tops. Then cover the dough and chill it at 40°F for 30 minutes, shifting the dough once at minute 15 so the center cools as quickly as the edges. The Browned Butter Halloween Candy Cookies dough will feel firmer and the candy pieces will stay suspended instead of sinking into a greasy base. Don't rush it. Under 20 minutes and the butter stays too soft, so the cookies can spread into thin disks. You'll still smell that toasted butter when you press the surface. Chill 30 minutes because firm fat slows spread before the edges set.

Scoop the chilled dough at about 95 grams per portion and make exactly 12 mounds. Keep the dough close to 40°F while you portion it, and roll each mound only 3 or 4 turns between your palms so the surface stays craggy. Press 2 or 3 pieces of the reserved M&M's Ghoul's Mix candies into each top, then space the mounds about 3 inches apart before baking. Each mound should hold its shape with rough edges and visible candy, while the center still yields slightly when pressed. Keep them rough. If the dough warms above about 55°F during shaping, chill the trays for 10 minutes before they go into the oven. Pack the balls too tightly and the centers bake dense. Loose shaping keeps the centers tender because compacted dough bakes denser.

Bake at 350°F for 12 to 14 minutes, then swap the two trays between oven racks at minute 7 so every cookie colors evenly around its edges. Pull them when the edges are deep golden and the centers still look slightly puffed and soft. Let them sit for 10 minutes, then move all 12 cookies to a serving plate so the bottoms can finish setting without trapping excess heat. Browned Butter Halloween Candy Cookies should smell nutty and chocolatey, with glossy candy pieces and uneven golden edges around softer centers. That's the cue. Go past 15 minutes and the middle loses that chewy bend as it cools. The cookies will firm during the 10 minute rest. Pull at soft centers because residual heat finishes the set without drying them.