Add the softened/room temperature butter to a large mixing bowl or bowl of a stand mixer.
Add in both sugars and cream together with an electric mixer for about 30 seconds.
Beat in the apple sauce and vanilla.
Spoon and level the flour to measure and add to the bowl with the salt and baking soda. Stir to combine. Add graham cracker crumbs and stir to combine.
Fold in the chocolate chips. Add the dough to the fridge for 15 minutes. Avoid letting it sit for longer than 20 or it will firm up too much and the cookies won't spread properly.
When the dough is in the fridge, preheat the oven to 350 degrees Fahrenheit.
After 15 minutes, take a medium cookie scoop and scoop the dough into your hand. Flatten it out slightly, stick in about 3-4 mini marshmallows and roll up into a ball, trying to get some marshmallow to show on top. Alternatively, just use half of one large marshmallow and mush it into the dough ball. Place on a baking sheet lined with parchment paper.
Repeat until all dough has been used. I suggest baking no more than 6 cookies at a time since they will spread.
Bake for 13-17 minutes, I usually do 14 in my oven. The edges should be golden brown and the centers nice and soft. They will seem quite soft when they come out of the oven, but these firm up much more than your average cookie, so take them out on the early side if you prefer a chewy texture. When there's a few minutes left on the timer, check the cookies and if you notice they aren't spreading a lot (see notes- this is usually because of the type of marshmallows), then take the cookie sheet and slam it down onto the oven rack 2-3 times to encourage spreading.
Once done, sprinkle on some chopped up chocolate (it'll melt right on top) and use a round cookie cutter to scoot around the cookies into a perfectly round shape. Let cool on the baking sheet for about 15-20 minutes, then transfer to a cooling rack with a spatula to finish cooling. Enjoy!