Spread the cookies, pretzels and raisins evenly onto a lightly greased small baking sheet. Melt chocolate in a bowl set over a pan of simmering water, or in the microwave, stirring frequently until melted. Remove from the heat while there are still a few chunks, and stir until smooth. White chocolate burns easily.
Drizzle chocolate with a spoon over the goodies in the pan, spreading the top flat to coat evenly. Top with candy corn and sprinkles. Let cool until firm. Break into pieces and store in an airtight container.