Heat hemp milk in a saucepan over medium heat until warmed, about 5 minutes. Remove saucepan from heat and stir chia seeds into hemp milk. Let mixture sit, stirring occasionally every hour, until thickened, 2 to 3 hours.
Mix cocoa powder, agave nectar, baking chocolate, almond extract, vanilla extract, salt, and pepper into chia-milk mixture; blend in a high-powered blender until smooth. Cool mixture in refrigerator for 3 hours.
Blend mixture in an ice cream maker according to manufacturer's instructions until frozen, 25 to 30 minutes.