These are super easy, high-altitude-friendly Oreo Cupcakes!
Preheat your oven to 350 degrees, and line a 12-cup muffin tin with paper cupcake liners. Set aside.
In a large bowl, whisk together the sugar, melted butter, and canola oil until well combined. Whisk in the egg until just combined. In a medium bowl, whisk together the flour, salt, baking powder, and baking soda. In a small bowl, stir together the milk and vanilla extract.
Add about 1/3 of the dry ingredients to the butter/sugar mixture and stir until just mixed through. Add in about 1/2 of the milk mixture, and stir to combined. Repeat this alternating mixing until all of the milk is added, and you have about 1/3 of the flour mixture left. Then, add in the remaining flour mixture along with your chopped Oreos, and use a spatula to fold everything together until there are no more pockets of flour remaining.
Scoop your batter into your prepared cupcake liners. The batter will come pretty close to the top of each cupcake cup, but don't worry, that's how it's supposed to be! You should get 12 cupcakes from this batter. Bake the cupcakes for 18-20 minutes, or until a toothpick inserted into a cupcake comes out clean. Cool the cupcakes for 10 minutes in the pan, and then transfer them to a wire rack to cool completely.
In a large heat-proof bowl, or the bowl of a stand mixer, set over a small pan of boiling water to make a double broiler, whisk together the eggs whites and sugar until the sugar is dissolved completely, about 5-8 minutes. You can pinch some of the mixture between your fingers to feel if the sugar is dissolved.
Remove the bowl from the double broiler and place it on your stand mixer if you have one, or use an electric hand mixer. Use the whisk attachment to beat the mixture for 5-8 minutes, or until it is completed cooled, and has become a thick meringue mixture that holds a peak.
With the mixer running, add in the butter very slowly, only about 1 tablespoon at a time. Once all the butter has been added, increase your speed to medium-high, and beat until the mixture becomes fluffy and smooth. This can take a while, and the mixture will look broken at several stages, but will eventually come together! It can take up to 10-15 minutes at this point, so give it some time. Then, beat in the salt and vanilla extract. Fold in the Oreo crumbs by hand until well distributed. Frost your cupcakes as desired, and top each cupcake with a whole Oreo. Enjoy!