In a medium saucepan set over medium-low heat, add the butter, coconut sugar, maple syrup, cocoa powder, and almond milk. Whisk, allowing the butter to melt slowly, until there are no lumps, 1 to 2 minutes. Continue to cook for about 8 minutes, whisking often. Once the mixture is simmering, whisk constantly and cook for about 1 minute or until the sugar is completely dissolved. Reduce the heat to low. Add the peanut butter and vanilla extract. Whisk until smooth and combined. The mixture should be thick and fudgy. Remove from the heat.
Add the salt, oats, and chopped peanuts, stirring vigorously until combined. The mixture should be looser than cookie dough. It will set up in the freezer. Set aside for about 5 minutes, allowing the oats to soak up some of the chocolate mixture.
Using a large cookie scoop (about ¼ cup), spoon the mixture onto a parchment paper-lined baking sheet. Top with chocolate chunks, pressing them into the surface of the cookies, and sprinkle with flaky salt. Transfer to the freezer for at least 30 minutes to set. Once the cookies have set, remove from the baking sheet and store in an airtight container in the fridge or freezer for up to 1 week.