In a small skillet over medium heat, sear the Canadian bacon for 2-3 minutes per side until the edges are golden and crispy.
Lightly toast the sprouted grain bread until firm and warm, then place it on a serving plate.
In the same skillet used for the bacon, quickly sauté the baby spinach for 1 minute until just wilted, then layer it over the toasted bread.
Fill a medium saucepan with water and add the white vinegar; bring to a very gentle simmer.
Carefully crack the two eggs into the simmering water and poach for 3 minutes until the whites are set but the yolks remain runny.
While the eggs poach, create the sauce by whisking the egg yolk, Greek yogurt, lemon juice, sea salt, black pepper, and cayenne in a small heat-safe bowl.
Set the bowl over the pot of simmering water (double boiler style) and whisk constantly for 2 minutes until the sauce is thick and velvety.
Place the crispy Canadian bacon and poached eggs on top of the spinach, drizzle with the warm hollandaise sauce, and serve immediately.