Preheat the oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a large bowl, combine the rolled oats, whole wheat flour, baking soda, ground cinnamon, and salt. Mix well.
In a separate bowl, whisk together the melted butter, brown sugar, honey, egg, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined.
Fold in the raisins and chopped walnuts evenly throughout the dough.
Using a tablespoon, drop cookie dough onto the prepared baking sheet, spacing them about 2 inches apart.
Gently flatten each cookie with the back of the spoon to about 1/2 inch thickness.
Bake in the preheated oven for 18 to 20 minutes, or until the edges are golden brown and the centers are set.
Remove from the oven and allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.