Combine dry ingredients. In a medium sized mixing bowl, whisk your flour, baking soda, salt, and cinnamon together. Set aside. 2 cups (240 g) all purpose flour 1 teaspoon baking soda 1 teaspoon salt 1 teaspoon cinnamon
Combine wet and dry ingredients. In a second bowl whisk together your melted butter and sugars until evenly combined, about 1-2 minutes. Add in your eggs and vanilla. Whisk to combine. 1 cup (2 sticks, 226 g) unsalted butter 1 cup (213 g) packed light brown sugar ½ cup (100 g) granulated white sugar 2 large eggs 2 teaspoons vanilla extract
Combine wet and dry mixtures.. Add in your dry ingredients, and with a wooden spoon or spatula stir to combine. Be careful to not overmix.
Add oats and raisins. Stir in your oats, and raisins with a rubber spatula or wooden spoon. 2 cups (200 g) old-fashioned oats 1 ½ cups (234 g) raisins
Refrigerate dough. Chill the cookie dough for at least 2 hours, up to 24 hours. Simply cover the bowl and refrigerate the cookie dough for 24 hours. You can also scoop before chilling (I let the dough rest for 10 minutes to thicken then scoop). When ready to bake, allow the dough to sit at room temperature for several minutes to allow for easy scooping.
Prep oven and pans. Position a rack in the center of your oven, and preheat the oven to 350°F/177°C. Prepare a cookie sheet with parchment paper (or you can use a silicone baking mat)
Bake. Use a medium scoop (about 2 Tablespoonsful) and place 12 cookies about 2 inches apart onto a cookie sheet. Bake on the middle rack for 10-12 minutes for smaller cookies until edges are set and golden brown and middles still look slightly soft. Allow cookies to cool 5 minutes on the cookie sheet before transferring the cookies to cool on a cooling rack.