Preheat oven to 350 degrees F
Line 2 baking sheets with parchment paper
In a large mixing bowl, mix flour, baking soda, baking powder and salt with a large spoon
Place butter in large glass bowl, then place in microwave. Use defrost setting to soften butter without fully melting it (1.5 min) - OR - microwave on high for a total of 30 seconds, pausing every 10 seconds to prevent butter from melting.
Remove glass bowl from microwave and add sugars
Mix with metal spoon or whisk until homogenous
Add egg, vanilla extract, cinnamon, and nutmeg to sugar mixture, then mix thoroughly
Add 1/2 dry ingredients (flour, soda, powder and salt); mix thoroughly
Add the rest of dry ingredients; mix thoroughly
Fold in oats and raisins until evenly distributed
Use a tablespoon or a #40 cookie scoop to make dough balls. Roll dough into small balls (about 1.5 inches in diameter)
Place dough balls 3-4 inches apart on baking sheets
Bake until tops are golden and edges are crisp (~12-15 min)