Prepare and bake your pan of brownies and allow to cool completely.
Use the heart cutters to cut out hearts, getting as close to the edges of the pan and other cutouts as you can to maximize your brownie hearts.
Arrange brownie hearts on a parchment-lined baking sheet.
Add the white chocolate chips to a microwave safe bowl and heat in the microwave for 30 second intervals, stirring well between each heat session, until fully melted. Do not overheat or this won't set up without being refrigerated. You want it to be just melted, not super hot.
Use a spoon to carefully drip melted chocolate into the center of the brownies (one at a time), then use the tip of the end of the spoon to work the chocolate to the edges. Doing this step carefully and slowly will ensure that you don't make a mess dripping chocolate down the sides of the brownie.
Immediately top with sprinkles as the chocolate will set quickly.
Allow chocolate to fully set, then enjoy!