Preheat oven to 350°F (175°C). Line two baking sheets with parchment paper and set aside.

In the bowl of a stand mixer fitted with the paddle attachment (or using a hand-held mixer), beat the softened butter, brown sugar, and honey together until the mixture is smooth, glossy, and fully combined for 2-3 minutes.

Add the egg and beat until just incorporated, about 30 seconds. Mix in the vanilla extract until combined.

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

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined, taking care not to overmix.

Gently fold in the mini M&Ms. Drop rounded tablespoons of dough onto the prepared baking sheets, leaving 2 inches of space between them. Press a few extra M&Ms on top of each cookie if desired.

Bake for 8-10 minutes, or until the edges are lightly golden and the centers are still soft. Let cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely.