Halve apples cutting them from the stem down. Use a melon baller to hollow the apples, leaving enough flesh for the shells to hold their form. Squeeze lemon juice over the apples to reduce browning; arrange onto a baking sheet.
Stir hot chocolate into boiling water in a saucepan off heat until smooth. Stir coconut milk into the cocoa mixture. Sprinkle gelatin over the cocoa mixture and leave undisturbed 1 to 2 minutes.
Place saucepan over medium-low heat. Stir gelatin into the cocoa mixture. Add sugar; stir to dissolve sugar into the mixture. Drop yellow food coloring into the mixture. Remove saucepan from heat and cool mixture slightly.
Pour cocoa mixture into the apple shells. Refrigerate 8 hours to overnight.
Cut each apple half into 4 wedges; serve immediately.