Ensure the 3 large eggs are at room temperature and separate them: place the yolks in a large bowl and the whites in a clean bowl.
Whisk together the egg yolks, 1 cup Greek yogurt, 4 tablespoons whole milk, 2 1/2 tablespoons sugar, 1/2 teaspoon salt, 1 teaspoon vanilla extract, and 2 teaspoons baking powder in the large bowl with the yolks until smooth.
In a separate large bowl combine 1 cup all-purpose flour and 1/3 cup malted milk powder. Add 1 cup sliced bananas and 1 cup semi-sweet chocolate chips and toss to coat the banana slices evenly with the dry mixture.
Add the flour/banana/chocolate mixture to the yogurt mixture and stir just until combined. Do not overmix; the batter will be thick and may still have some lumps.
Using a handheld mixer or the whisk attachment of a stand mixer, beat the reserved egg whites until they hold soft peaks.
Gently fold the beaten egg whites into the batter with a rubber spatula, in two additions if desired, folding just until no large streaks of white remain.
Heat a large skillet over medium heat. Melt some of the 4 tablespoons of butter in the skillet to coat the surface; add additional butter from the 4 tablespoons as needed between batches to prevent sticking.
Spoon or ladle about 1/3-cup portions of batter into the skillet, leaving space between pancakes so they don’t run together. Cook until the edges begin to brown and the tops form bubbles.
Flip the pancakes and cook the second side for 1–2 minutes, until golden and cooked through. Transfer cooked pancakes to a plate and keep warm while you cook the remaining batter, adding more butter as needed.
Serve the pancakes immediately with your preferred toppings.