Preheat the oven to 350°F (175°C). Line baking sheets with parchment paper or silicone mats.

If you're roasting nuts, spread them on a tray and roast at 350°F for 6–8 minutes until fragrant; let cool.

In a medium bowl, whisk together the flour, baking soda, baking powder, and salt.

In a large bowl or stand mixer, cream the softened butter with the granulated and brown sugars until light and fluffy, about 2–3 minutes. Scrape down the sides as needed.

Beat in the eggs one at a time, then mix in the vanilla and orange zest (if using). Don't overbeat once the flour is added—mix just until combined.

Gradually add the dry ingredients to the wet, mixing on low speed or folding with a spatula until just incorporated.

Stir in 1 1/2 cups of M&Ms and any toasted nuts or coconut. Reserve 10–12 M&Ms to press on top of cookie dough balls right before baking.

For thicker cookies, chill the dough for 30 minutes to an hour. If you're short on time, you can bake immediately.

Use a cookie scoop to portion dough into 1.5-tablespoon balls and place them 2 inches apart on the prepared trays. Press reserved M&Ms on top.

Bake at 350°F for 9–12 minutes, rotating trays halfway through. Cookies should be golden at the edges and slightly underbaked in the center.

Let cookies cool on the baking sheet for 5 minutes to set, then transfer to a cooling rack.