Soften the butter slightly by microwaving for 15 seconds on high. Place the butter in a large mixing bowl and add the brown sugar. Cream the butter and brown sugar together with an electric mixer on high speed until smooth and creamy. Mix in the eggs, one at a time, then the vanilla. Stop the mixer and add the flour, baking soda, salt, cinnamon, and nutmeg on top of the wet ingredients. Using the mixer on low, mix the dry ingredients in until the dough is just smooth. With the mixer on low speed add in the oats then the raisins until just mixed.
Using an 18-8 scooper, form 2 1/4 inch diameter balls and place on a parchment lined baking sheet. When all the balls are formed, place in a freezer overnight. Once frozen, transfer the dough balls to a gallon freezer bag and store frozen until ready to bake.
When ready to bake, removed the desired number of cookies and place well spaced on a parchment covered baking sheet, no more than 6 per 12 x 18 inch baking sheet. Preheat the oven to 350 F then bake for 22-24 minutes or until the cookies look firm and dry around the edges. Remove from the oven and let stand on the baking sheet for 10 minutes or so then remove to a wire rack to fully cool. Makes about 28 large cookies.
