Heat the oven to 425°F (218°C). Line two baking sheets with parchment paper. Cook the bacon in a large skillet over medium-low heat until crisp but not too dark. If using Canadian bacon, dice it into small pieces. Transfer the bacon to a plate lined with paper towels and reserve 1/4 cup of the rendered fat. When the bacon is cool, chop it to make 1/2 cup.
Bring the milk, 1/2 cup of water, the butter, and the reserved bacon fat to a simmer in a medium saucepan over medium heat. Stir in the salt, onion powder, sugar, and cayenne.
Add the flour and, using a wooden spoon, stir very quickly in one direction. The flour will quickly absorb the liquid and form a dough. Continue stirring to cook the flour and simmer off more of the moisture until the dough pulls away from the sides of the saucepan, about one to two additional minutes.
Transfer the dough to the bowl of an electric mixer fitted with a paddle attachment. Add the eggs one at a time, mixing on medium speed until each is incorporated into the dough, which will change from shiny to sticky as the eggs are added. On low speed, stir in 1 cup of the Parmesan and the bacon (or Canadian bacon) until just combined.
Using a small ice cream scoop (about 2 inches [5 cm] in diameter), scoop the dough onto the prepared baking sheets. Top the gougeres with an equal amount of the remaining 1/4 cup of Parmesan.
Bake until puffed and golden, about 20 to 25 minutes. Serve warm.