Preheat oven to 375 degree Farenheit.
Line baking sheet with parchment paper. Place a bowl on a food scale, and measure all ingredients into bowl. Add in the spices by using measuring spoons. Add in the chopped nuts.
In bowl of mixer, and using the flat paddle attachment, add ingredients from bowl: oats, brown sugar, flour, butter, cinnamon, nutmeg, cinnamon, pecans and salt. Mix just until combined. Mixture should be crumbly.
Spread the crumble out on prepared pan. Scatter around pan so crumble bakes evenly. Bake for 8-10 minutes, stirring once halfway through.
Let cool completely. Store in airtight container in fridge for up to two weeks, one month in the freezer.