Heat the cream: Add the heavy cream and milk to a saucepan over medium heat. Whisk occasionally until it just starts to simmer with bubbles along the edges, then remove from the heat.
Temper the eggs: Whisk the egg yolks, honey, arrowroot powder, and vanilla in a medium bowl. While continuously whisking, very slowly pour half of the hot cream mixture into the bowl. Don’t pour too fast or the eggs will curdle.
Stir together: Return the tempered egg mixture to the saucepan and stir together over medium-low heat for 1 to 3 minutes, or until the custard is slightly thickened. Note: the custard will continue to thicken once removed from the heat.
Serve: You can serve the custard warm drizzled over cake, pie, or other desserts or you can chill it and serve cold. If chilling, transfer the custard to a bowl and cover the top (so that it’s touching the custard) with plastic wrap to prevent a skin from forming. Chill for 4 hours or overnight. Then, spoon individual servings in glasses to serve.