Preheat your oven to 375°F (190°C) and line two large baking sheets with parchment paper.

In a large mixing bowl, cream together softened unsalted butter, light brown sugar, and granulated sugar until smooth and creamy.

Add one whole egg, an additional egg yolk, and pure vanilla extract into the creamed mixture and mix until well combined.

In a separate bowl, whisk together whole wheat flour, all-purpose flour, cinnamon, salt, and baking soda until combined.

Gradually add the dry ingredients to the wet mixture, mixing on low speed until just combined.

Fold in the old-fashioned oatmeal, raisins, and semisweet chocolate chips until evenly distributed.

Drop rounded balls of cookie dough onto prepared baking sheets, spacing them 2-3 inches apart.

Bake in the preheated oven for 9-12 minutes, checking for golden brown edges and soft centers.

Remove from the oven and let cool on the sheets for about 5 minutes before transferring to wire racks to cool completely.