Line an 8x8-inch straight-sided baking pan with parchment. Leave enough parchment to overhang the sides to easily lift the chilled fudge from the pan and slice into 1-inch pieces.

In a large microwave-safe bowl, stir together the white chocolate chips and sweetened condensed milk. This helps the white chocolate heat and melt more evenly.

Heat for 1 minute, stir, heat for another 30 seconds, then stir again. At this point, your white chocolate chips will not be completely melted.

Add the molasses to the bowl and heat for an additional 30 seconds.

Stir in the vanilla, cinnamon, ginger, nutmeg, and cloves until smooth. The residual heat will continue to melt the last few small pieces of white chocolate as you stir. If needed, heat for an additional 20-30 seconds, being careful not to overheat the white chocolate, as it can seize or burn.

Transfer the gingerbread fudge to the prepared pan and spread it into an even layer.

Sprinkle the non-pareils evenly over the top of the fudge and gently press down. This will help keep the non-pareils in place once the fudge is chilled and sliced.

Refrigerate the fudge for 2 hours, or up to overnight, until fully set.

Remove the fudge from the pan using the overhanging parchment, slice into 1-inch pieces, and serve.

Store in an airtight container at room temperature for up to 1 week. For longer storage, refrigerate for up to 1 month. If using the seasonal non-pareils as a garnish, refrigeration may cause the colors to bleed onto the surface of the fudge as it comes to room temperature before serving.