Line a baking sheet with parchment paper. Set the prepared sheet near your work area so the freshly dipped cookies can be transferred without carrying them far.

Melt the white candy coating in a microwave-safe bowl at 50% power in 30-second intervals, stirring after each interval. Continue with 15-second intervals until smooth, taking care not to overheat or scorch it.

Dip each Oreo completely, or coat only the top and sides, using a fork or dipping tool. Tap gently to remove excess coating, then place each cookie on the parchment-lined baking sheet.

Allow the white coating to set for 10–15 minutes at room temperature, or refrigerate the cookies for about 10 minutes. The coating should feel firm before the red decoration is added.

Melt the red candy melts in a separate bowl. Stir in 1 teaspoon of vegetable shortening or paramount crystals only if the red coating is too thick to flick easily.

Dip the bristles of a clean, food-safe toothbrush or pastry brush into the red coating and flick it over the white-coated Oreos. Use a fork or bamboo skewer for smaller streaks and drops, and protect the surrounding work area from overspray.

Let the cookies set completely for about 15 minutes at room temperature or 10–15 minutes in the refrigerator. Store the finished cookies in an airtight container at cool room temperature.