Prepare the raisins: Add the butter to a medium-sized sauce pot and place it over low-medium heat. Once the butter has melted, turn the heat to low. Add the raisins, vanilla and cinnamon and stir to blend. Cover and let this gently simmer for 5 minutes. Then turn the heat off, keep the pot covered, and let it sit for 55 minutes.
Preheat oven and prep baking sheets: While the raisins are soaking, preheat the oven to 350°F. Cover 2 baking sheets with parchment paper, set aside, and adjust two racks towards the center of the oven.
Mix dry ingredients: In a medium-sized mixing bowl, combine the flour, salt and baking soda. Set aside. Add both sugars to a large mixing bowl and set aside.
Combine all of the ingredients: Once the raisins are done soaking, add the mixture to the bowl with the sugar and mix to blend. Then add the eggs and mix until they are fully incorporated. Add the dry ingredients to the wet ingredients. Mix just until you no longer see any dry spots.
Shape the batter: Use a cookie scoop (approximately 2 inch) to drop the batter onto the parchment-lined baking sheets. Gently press each one down a bit with the palm of your hand. There should be a couple of inches between them. Bake the cookies: Bake in the preheated 350°F oven until they're set and slightly golden along the edges, about 12 minutes.
Cool the cookies: Let them cool on the baking sheet for at least 10 minutes and then transfer them to a cooling rack.