Put oil and popcorn kernels in a large pot over medium-high. When the first kernel pops, cover the pot and remove it from the heat for about 30 seconds.
Place pot back on the stove and once kernels start popping, vigorously shake the pot back and forth, keeping it on heat. Once popping slows, take pot off the heat and remove cover. Put popped popcorn in a large bowl.
Melt white chocolate/wafers either in a double boiler or by putting them in a heatproof metal bowl placed over a saucepan of gently simmering water (don't allow water to touch bowl). Alternatively, you can melt at intervals in bowl in microwave.
Drizzle melted chocolate over popcorn and toss with crumbled Oreo cookies, candy corn, and sprinkles.