Place the butter, white sugar, and brown sugar in a large bowl. Using an electric mixer, beat the ingredients until the mixture is fully combined and becomes light and fluffy. This should take about 3 or 4 minutes. Using softened butter should help the process along. If your butter is cold, you can  soften it by microwaving it for about 15 seconds. Keep the mixer running and beat the batter until the eggs and vanilla are thoroughly incorporated. In a separate bowl, stir together the flour, salt, cinnamon, baking soda and oatmeal until the ingredients are completed mixed. Pour 1/3 of the dry mixture into the bowl with the wet ingredients and mix on low (or stir by hand) until blended. Do the same with the next 1/3 of the bowl, and finish by mixing in the last 1/3. Don't mix the batter on high - do it slowly! This way you can make sure the cookies will come out light and delicious, rather than tough. Last but not least, stir in the 1 1/2 cups of raisins - again, make sure not to overmix. Use a cookie scoop, a small measuring cup or a tablespoon to scoop out the cookies onto a nonstick cookie sheet. Space them so that there are 2 inches (5.1 cm) in between each cookie, since they'll spread as they bake. You'll end up with about 2 dozen cookies, so you may need to bake them using two separate sheets or one batch at a time.  If you don't have a nonstick cookie sheet, grease the cookie sheet before scooping. You can also line your cookie sheet with parchment paper. Make the cookies bigger if you'd like! Use a 1/2 cup measuring cup to scoop out giant oatmeal cookies that will be soft in the middle and crispy around the edges. Place them in the preheated oven and bake for 10 - 12 minutes, until they're brown around the edges. Remove them from the oven and allow them to cool.

Summary:
Preheat the oven to 350 degrees. Beat the butter and sugars. Add the eggs and vanilla. Mix the dry ingredients. Add the dry ingredients to the wet ingredients. Stir in the raisins. Scoop out the cookies. Bake the cookies.