Line an 8×8 baking dish with parchment paper and lightly grease, then set aside.

In a large microwave safe bowl, add white chocolate chips, marshmallows, and butter, and microwave for 1 minute. Stir contents with a greased spatula then continue microwaving in 30 second increments, stirring in between, until mixture is fully melted and smooth.

Let mixture cool for 1 minute then mix in the chopped gumdrops.

Transfer mixture to the prepared baking dish and use a spatula to press into a flat and even layer.

Cover with plastic wrap and chill for a minimum of 2 hours.

Lift candy out of the dish using the parchment paper. Remove paper and slice into small bite-sized squares.

Keep in an airtight bag or container until ready to serve.