Set cookie molds and Oreo cookies out on a clean work surface. Cut a sheet of waxed paper or parchment paper and lay on the work surface.

Place almond bark in a microwave-safe bowl. Heat at 50% power for 1 minute. Remove from microwave and stir well. Microwave for 15 seconds longer at 50% power, then remove and stir. Repeat for 15 second intervals in the microwave and stirring until mixture is completely melted and smooth. (Instead of microwaving, you can also place almond bark in a double boiler over slightly simmering water, stirring frequently till smooth.)

Place a tablespoonful of the melted almond bark into the mold cavities, filling them about ⅓ full. Tap the mold on the table or kitchen counter to settle the chocolate, and remove any small air bubbles. Press one Oreo into each opening and center it both horizontally and vertically. The chocolate will rise up around the sides and only the top will be uncovered.

Add a smaller spoonful of the melted almond bark on top of each cookie, filling the mold and covering the cookies. Again tap the mold lightly on the work surface to remove air bubbles.

Scrape the excess chocolate off the mold with a flat edged spatula or a bench scraper.

Refrigerate the molds for 10-15 minutes. Remove from refrigerator and gently press on the back of the molds to release the cookies.

Place cookies on prepared wax paper and decorate as desired. I drizzle them with a bit more almond bark in contrasting color, then sprinkle with jimmies, sprinkles, crushed candy canes, etc.