Add blended oats, tapioca, and milk to a small pot and cook while constantly stirring on low heat. Reduce heat to low once the mixture begins to thicken after a few minutes, and mix until it forms a dough texture.
Add protein powder*, cacao, pitted dates, salt, cinnamon, and cooked oat mixture to a food processor, pulse a few times and then blend until dates break down and the mixture is homogeneous.
The mixture should be softer at this stage as it will harden in the fridge.
Transfer to a smaller baking sheet or any other form of choice where you can flatten it and form a rectangle.
Leave in the freezer for 10 minutes to harden.
Remove from freezer, transfer to the cutting board, cut into 8 even bars, and then return to freezer.
Melt chocolate in the microwave in 30-sec intervals, mixing between each until melted. Alternatively, melt using the double boiler method.
Add chopped peanuts to the melted chocolate.
Remove bars from the freezer and place them on a rack. Make sure to place parchment paper below the rack to collect all the chocolate that falls off the bars.
Cover the bars with melted chocolate and return to the fridge for a few minutes for the chocolate to harden, then enjoy.
Store leftovers in the fridge.
Notes
* Protein powders behave differently depending on the brand, type, and ingredients. For example, vegan protein powders absorb liquids faster than whey ones. Therefore, depending on the protein powder you use, feel free to add oats or milk to reach the desired consistency.