01 -
Preheat oven to 350°F. Line a 10x15-inch baking dish with foil, leaving 2-inch overhang on two sides. Grease foil with nonstick spray. Whisk flour, cocoa, and salt. Melt butter and semisweet chocolate over medium heat until smooth, cool 10 minutes. Stir in sugar, then eggs. Fold in flour mixture in two additions. Pour into pan and bake 20-25 minutes until a toothpick shows a few crumbs.
02 -
Sprinkle bittersweet chocolate chips evenly on warm brownie. Let melt 5 minutes, then spread melted chocolate with offset spatula. Cool completely on rack for 1 hour, then refrigerate 30 minutes to set. Lift brownie from pan using foil overhang.
03 -
Lightly grease a 16-inch parchment with nonstick spray, place chocolate side down. Using a paring knife, cut a 9-inch circle from half the brownie for the base. Position chocolate side up in a 9-inch springform pan and secure side. From remaining brownie, cut two 2 1/2-inch equilateral triangles for eyes, one 2-inch triangle for nose, and a 5-inch half-moon shape for mouth with offset teeth. Smooth cracks with a heated offset spatula if needed.
04 -
Soften gelatin in 1/4 cup water, about 5 minutes. Blend cream cheese, pumpkin puree, confectioners' sugar, sour cream, vanilla, and salt in a food processor until smooth. Microwave gelatin 30 seconds until melted, stir, then incorporate into mixture. Process 30 seconds to combine.
05 -
Pour filling over brownie base in springform pan. Press brownie eyes, nose, and mouth gently into batter, level with surface, avoiding batter contamination. Refrigerate at least 4 hours or overnight until fully set.
06 -
Tint vanilla frosting with 1-2 drops green gel until vine color achieved. Transfer to pastry bag fitted with small round tip and pipe a curly vine along the top edge. Insert chocolate square about 6 mm from top edge to form stem.