In a spacious mixing bowl, combine the melted butter, room temperature egg, pure vanilla extract, and softened cream cheese. Whisk them together thoroughly until the mixture is smooth and beautifully blended. This creamy blend is your key to extra moist cookies!
Gradually incorporate the strawberry cake mix into the wet ingredients, adding about half of the box at a time. Mix gently until everything is just combined, being careful not to overmix the dough.
With a spoon or spatula, carefully fold in the white chocolate chips and M&Ms by hand. This ensures they're evenly distributed throughout your vibrant pink dough.
For the best cookie texture and easier handling, cover your dough and place it in the refrigerator to chill for at least one hour. This step helps prevent your cookies from spreading too much during baking.
When you're ready to bake, preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper to prevent sticking.
Scoop and roll the chilled dough into small, uniform 1-inch balls. Arrange them on your prepared baking sheet, leaving a little space between each one to allow for slight expansion.
Bake for 9 to 10 minutes. The cookies should look set and softly puffed, but their tops should not brown. The bottoms may have a light golden hue.
Allow your freshly baked cookies to cool on the baking sheet for a few minutes before carefully transferring them to a wire rack to cool completely. Enjoy these easy, homemade, and perfectly portioned sweet treats!