Preheat your oven to 375°F.
In a large mixing bowl, cream together the softened butter with both sugars until the mixture is light and fluffy. Add the eggs one at a time, followed by the vanilla extract, beating until well combined.
In a separate bowl, whisk together the flour, ground oatmeal, baking soda, baking powder, and salt. Gradually incorporate the dry mixture into the wet ingredients, beating until fully combined. Stir in the raisins and chopped walnuts until evenly distributed in the dough.
Shape the dough into balls about 1 to 1 1/2 inches in diameter and place them 2 inches apart on ungreased baking sheets.
Bake in the preheated oven for 10-12 minutes or until the edges are lightly golden.
Allow the cookies to cool on the baking sheets for about 1 minute before transferring them to a wire rack to cool completely.
This recipe yields approximately 4 dozen cookies. Enjoy!