Mise en place. Preheat oven to 350˚F and line a baking sheet with parchment paper. Then, measure out your ingredients before you begin.
Dry ingredients. Whisk the flour, baking soda, cinnamon and salt together until evenly distributed. Then, stir in the oats. Set aside.
Cream the butter. In a large bowl with an electric mixer, beat the butter and sugars at a medium speed until light and fluffy, scraping the sides as needed.
Wet ingredients. Next, add the egg and vanilla extract. Continue to beat until the mixture is combined.
Combine everything. Then, add the oat mixture, about a 1/4 at a time, mixing with each addition until incorporated. Be careful not to over mix, and scrape the sides of the bowl as needed.
Add the mix-ins. When the dough is combined, stir in the raisins and chocolate chips until evenly distributed.
Bake the cookies. Using a cookie scoop, drop 2-tablespoons sized balls onto prepared baking sheet and bake cookies for 10-12 minutes, or until cookies are set on the top but still soft. Remove from the oven and allow them to sit on the baking sheet for about 5 minutes, before transferring to a cooling rack.