Combine sugar, 1/2 teaspoon cinnamon, nutmeg, and allspice in a bowl.
Whip egg whites with an electric mixer on high speed until soft peaks form. Reduce speed to medium and beat, gradually adding 1/2 of sugar mixture, until stiff peaks form.
Beat egg yolks in a separate bowl until thick and lemon colored. Mix remaining sugar mixture into the yolks. Fold yolk mixture into the egg whites. Add milk and half-and-half; combine gently. Garnish with remaining cinnamon.
