Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

In a mixing bowl, whisk together 2 cups of all-purpose flour, 1 teaspoon of baking soda, and 1/2 teaspoon of salt.

In another bowl, cream together 1/2 cup of softened unsalted butter, 1/2 cup of granulated sugar, and 1/2 cup of packed brown sugar until light and fluffy.

Mix in 1 teaspoon of vanilla extract and 2 large eggs, one at a time, blending well.

Gradually add the dry mixture to the wet ingredients, stirring until just combined.

Fold in 1 to 2 cups of M&M candies and chopped nuts, if desired.

Drop rounded balls of dough onto baking sheets, spacing them about 2 inches apart.

Bake for 10 to 12 minutes, until edges are golden and centers are soft.

Cool cookies on baking sheets for 5 minutes, then transfer to wire racks to cool completely.

Store leftovers in an airtight container at room temperature.