In a small bowl, combine the softened salted butter with maple syrup, honey, white miso paste, vanilla, and a pinch of sea salt flakes. Mix well until everything is nicely blended. Set aside to allow the flavors to meld.
In a clean mixing bowl, add the egg whites and cream of tartar. Using an electric mixer or whisk, beat the egg whites until soft peaks form. Gradually add 3 tablespoons of caster sugar while continuing to beat until stiff peaks form.
In another bowl, whisk together the egg yolks, milk, vanilla extract, and 2 tablespoons of caster sugar until smooth and well combined.
In a separate bowl, sift together the flour and baking powder.
Gently fold the egg yolk mixture into the dry ingredients until just combined. Be careful not to overmix; you want a few lumps to remain.
Gently fold in the whipped egg whites into the batter in three additions.
Heat a non-stick skillet over low heat and lightly oil the surface. Use a ring mold or a large spoon to pour the batter into the skillet, creating thick pancakes. Cover with a lid and cook for about 4-5 minutes on one side until they rise and develop a golden-brown color. Carefully flip and cook for another 4-5 minutes.
Once the pancakes are cooked, stack them high on a plate and serve with a generous dollop of the miso butter. Drizzle with extra maple syrup and honey for an indulgent finish.
