1 (3-ounce) package lemon-flavored gelatin dessert
1/4 cup boiling water
1 cup vodka, divided
1 1/4 cups mango nectar
2 3/4 cups orange soda, chilled
1 (15-ounce) can full-fat coconut milk, chilled overnight
1 tablespoon granulated sugar
Candy corn, for garnish
Combine the gelatin and water in a large bowl, stirring until gelatin is dissolved. Stir in 1/2 cup of the vodka and the mango nectar. Pour the mixture into a tall, clear 2-quart pitcher. Cover and chill until thickened but not set, about 2 hours.
Stir the remaining 1/2 cup vodka and orange soda together in a medium bowl or measuring cup. Press a large spoon against the side of the pitcher and gently pour over the back of spoon on top of gelatin layer.
Open the can of coconut milk, scoop out the firm layer of cream that has solidified at the top, and place in a bowl. (Save the rest of the can for another use.) Add the sugar and beat with an electric mixer until soft peaks form, 3 to 5 minutes. Spoon over the mixture in the pitcher. Garnish with the candy corn and serve.