Divide the Tanqueray Rangpur Lime Distilled Gin between four small heatproof glasses or teacups.
Tip the apple juice into a saucepan with the rest of the ingredients. Heat gently until simmering, then strain into a jug. Pour the mulled apple juice into the glasses with the gin and stir gently to combine. Garnish each glass with a bay leaf and half a lemon slice and serve warm.