Preheat the oven – Set the oven to 350°F (175°C) and line baking sheets with parchment paper to prevent sticking and ensure even baking.

Cream the butter and sugars – In a large bowl, beat the softened butter with brown sugar and granulated sugar until the mixture looks light, fluffy, and creamy. This step helps create a soft cookie texture.

Add eggs and vanilla – Beat in the eggs one at a time, mixing well after each addition. Stir in the vanilla extract until fully combined.

Mix the dry ingredients – In a separate bowl, whisk together the flour, baking soda, cinnamon, and salt so the leavening and spices are evenly distributed.

Combine wet and dry mixtures – Gradually add the dry ingredients to the butter mixture, mixing on low speed just until a soft dough forms. Avoid overmixing to keep the cookies tender.

Fold in oats and raisins – Using a spatula, gently fold in the rolled oats and raisins until evenly spread throughout the dough.

Shape the cookies – Scoop rounded tablespoons of dough and place them on the prepared baking sheets, leaving space between each cookie for slight spreading.

Bake until set – Bake for 10–12 minutes, or until the edges are lightly golden while the centers still look soft.

Cool before serving – Let the cookies rest on the baking sheet for a few minutes, then transfer them to a wire rack to cool completely.