Pour 3 to 4 tablespoons of cold half-and-half into a small jar or cup. Use a handheld milk frother for 20 to 30 seconds until the cream thickens and becomes foamy. It should be thick enough to float on the soda. If you don't have a frother, close the jar and shake it hard for about 60 seconds. Set the foam aside.

Fill a tall glass with about half a cup of crushed or pebble ice. This keeps the drink cold and helps hold the carbonation longer.

Tilt the glass and slowly pour 1 cup of cold Dr Pepper down the side. Pouring slowly helps keep the bubbles from fizzing over. Do not shake the can or bottle before opening.

Add 1 tablespoon of vanilla syrup to the soda. Stir gently just enough to mix it in without losing the carbonation. Avoid over-mixing.

Use the back of a spoon to gently place the foam on top of the soda. Don't pour it in; this keeps the foam separate and floating on the drink.

If you like, add a maraschino cherry on top. Serve the drink immediately with a straw. The foam will blend into the soda as you drink, giving you a creamy taste with each sip.