Melt white chocolate (or almond bark) in a double boiler or microwave. For a double boiler, boil water in bottom pan, add chocolate to top pan and stir continuously until chocolate is melted. If you are using a microwave, place the white chocolate chips in a microwave safe bowl and microwave in 30 second intervals. Stir between each interval, until the chocolate chips are fully melted. Add food coloring, a few drops at a time, to melted chocolate and stir until well blended (this step can be repeated several times until you achieve the desired color)(optional).
Spoon several tablespoons of melted chocolate into mold and “paint” the entire mold using the back of a small spoon - make sure you get the chocolate all the way to the top of the mold.
Allow molds to rest until chocolate is hardened. (If desired, speed up this process by placing molds in freezer for several minutes).
Gently pop chocolate spheres out of molds, being careful not to chip them.
Rotate bottom half of bomb on a warm plate to smooth edges.
Fill with ¼ cup hot chocolate mix and colored marshmallows to taste.
Rotate top half of sphere on warm plate to smooth edges and gently press two halves together. The slightly melted edge will seal the two halves. Do this step quickly so that the chocolate doesn’t start to dry before you get the halves together.
Drizzle tops with melted white chocolate and pastel/Easter sprinkles.