Place the chocolate in a food processor fitted with the S-blade attachment. Pulse until the chocolate is the consistency of coarse breadcrumbs, 20 to 25 pulses.
Turn the food processor on and run for 1 minute until the chocolate becomes a mass. Stop the food processor and use a clean spatula to break up the mass, scraping the bottom and sides. Leave the chocolate in the food processor for 1 minute without running or pulsing. Scrape down the sides and bottom of the processor after the 1-minute rest. Repeat this process 3 to 4 times until the chocolate is smooth, fluid, and reaches 90 to 91ºF on a digital instant-read thermometer. Do not let the chocolate go above 94ºF. If the chocolate is close to but not at 90ºF, briefly heat with a 10-second blast of warm heat from a hair dryer until it reaches the correct temperature.
Remove the food processor bowl from the base and the blade from the bowl. Continue scraping and stirring for 1 minute. Test the temper of the chocolate by spreading a small amount of chocolate in an even layer on a metal surface set over an ice pack. It should set within 3 minutes and be shiny and streak-free. If the temper test has some streaks, continue scraping and stirring for another minute and test again. The chocolate should maintain a temperature between 88 and 91ºF.
As the chocolate begins to cool, it will set on the sides of the food processor; as needed, scrape down the sides of the bowl again and briefly heat with a 10-second blast of warm heat from a hair dryer until it returns to 91ºF.
Stir two-thirds of the almonds and marshmallow creme into the chocolate, just to combine, and pour onto a sheet of parchment or a silicone mat set on a half-sheet pan inverted over cold packs. Top with the remaining third of the almonds and marshmallow creme. Cool until set, approximately 30 minutes.
Break into large pieces to serve. Store in an airtight container in a cool, dark place.