• In a large mixing bowl, beat butter with sugar, and brown sugar until creamy and smooth. You can also use a stand mixer with the paddle attachment. It takes about 1 minute to cream butter and sugar.
• Add in egg, vanilla extract, and almond milk and beat for 30 seconds to incorporate.
• Fold in the flour, baking soda, and salt and beat on low speed to incorporate.
• Fold in the mini chocolate chips and mini marshmallows and keep beating on low speed to evenly incorporate.
• Preheat oven to 350°F (180°C). Line a baking sheet with parchment paper and lightly oil with cooking spray. Set aside.
• Film the dough bowl with plastic wrap and chill cookie dough for 2 hours or overnight. Don't skip or the cookies overspread on the baking sheet.
• Form 12 cookie dough balls of the same size - about 1 1/2 tablespoons of batter each - scoop out the dough, oil your hands, and balls between your palms. Make sure the marshmallows are showing on top of the cookies, not the sides, or the marshmallows melt on the baking sheet and stick to it.
• Place the cookie dough balls on the baking sheet, leaving 1 inch apart. They expand a bit. Slightly flatten with your hand palm and replace any mini marshmallows showing on the sides of the dough onto the top.
• Bake for 10-12 minutes until they puff, spread, the top is dry, and they expand. Don't over-bake to keep them moist.
• Cool for 10 minutes on the cookie sheet, or then gently slide a flat spatula under them to transfer to a wire rack to cool completely. They are fragile, if too soft, cool down longer on the baking sheet before bringing them on the rack.

Storage

• Store in a glass mason jar at room temperature for up to 4 days or freeze in zip-lock bags for up to 3 months.