Prep the raisins. Place raisins in a bowl and cover with hot water (or warm apple juice) for 10 minutes. Drain well and pat dry with a paper towel. This keeps them plump inside the cookies.

Cream the butter and sugars. In a large bowl, beat the softened butter, brown sugar, and granulated sugar until creamy and slightly fluffy, about 2–3 minutes. This helps with chew and structure.

Add eggs and vanilla. Mix in the eggs one at a time until fully incorporated. Stir in the vanilla. Scrape the bowl so everything blends evenly.

Whisk dry ingredients. In a separate bowl, whisk the flour, baking soda, baking powder, cinnamon, and salt. This distributes the leaveners so the cookies rise evenly.

Combine wet and dry. Add the dry ingredients to the butter mixture and mix on low until just combined. Don’t overmix.

Stir in oats and raisins. Fold in the rolled oats, raisins, and nuts if using. The dough will be thick and chunky.

Chill the dough. Cover and chill for at least 30–45 minutes (up to 24 hours). Chilling is key for thicker cookies that don’t spread.

Preheat and prep pans. Heat the oven to 350°F (175°C). Line baking sheets with parchment paper or silicone mats.

Portion the dough. Scoop 2-tablespoon mounds (a heaping medium cookie scoop), rolling lightly into balls. For extra thickness, mound them slightly taller than wide.

Bake. Arrange 2 inches apart and bake 10–12 minutes, until the edges are set and the centers look slightly underbaked. They’ll finish setting as they cool.

Cool. Let cookies rest on the sheet for 5 minutes, then transfer to a cooling rack. They’ll be thick, soft, and perfectly chewy.