Preheat oven to 350℉. Line two cookie sheets with parchment paper or silicone baking mats.
In a mixing bowl, combine flour, oats, salt, baking soda, and malt powder (if using). Mix well.
2 c all-purpose flour, 1 1/2 c Old-fashioned oats, 1 tsp salt, 1 tsp baking soda, 1 T malt powder,
In the bowl of a stand mixer fitted with the paddle attachment (or a large mixing bowl using a hand mixer), cream butter, peanut butter, and both sugars until well combined and starting to get fluffy, about 2 minutes.
1/2 c butter,, 1/2 c creamy peanut butter, 1 c brown sugar,, 1/2 c granulated sugar
Add molasses, vanilla extract, milk, and eggs, and mix until light and fluffy, about 1-2 minutes.
2 tsp molasses, 2 tsp vanilla extract, 2 tsp milk or nondairy milk, 2 large eggs
Add dry ingredients and mix just until combined. Then fold in M&Ms, chocolate chips, and peanuts.
3/4 c plain M&Ms candies, 3/4 c semisweet chocolate chips, 1/2 c roasted salted peanuts
Using a large cookie scoop, or a spoon and your hands, form dough into about 3T balls and place 2" apart on a cookie sheet. Bake for 13-15 minutes, or until beginning to brown around the edges and set in the middle.
Remove from oven and let cool on cookie sheet for about 10 minutes, then move cookies to a cooling rack to cool completely. Store in an airtight container at room temperature for up to 5 days, or freeze for up to a month.