Combine the oats, flour, walnuts, yeast, salt, milk powder, and coconut in a large mixing bowl; set aside. Stir the sugar, water, canola oil, and peanut butter together in a small saucepan over low heat until the sugar has dissolved and the mixture is hot and smooth. Pour the peanut butter over the oats and stir until evenly combined. Spread out onto 4 baking sheets.
Bake in the preheated oven for 45 minutes, stirring every 15 minutes. Turn the oven off and allow the granola to cool in the oven until dry, about 3 hours.
