Special equipment: a square waffle iron
For the chicken: Preheat the oven to 425 degrees F. Line two baking sheets with parchment paper and spray generously with cooking spray.
Slice the chicken into 1 1/4-inch chunks. Stir the flour, chile powder, garlic powder, mustard powder, 2 teaspoons salt and 1/4 teaspoon pepper together in a shallow bowl. Crack the eggs into another shallow bowl and beat well. Place the panko in a third shallow bowl.
Toss the chicken chunks in the flour to coat, then shake the excess off. Dip a chicken chunk into the egg, let the excess drip off, and then place in the panko, turning and pressing the panko onto the surface to coat. Place the breaded chicken chunk on the prepared baking sheet and repeat with the remaining chicken.
Spray the chicken all over with cooking spray then bake, turning the chunks once halfway through, until the breadcrumbs are golden brown and the chicken is just cooked through, about 20 minutes.
For the waffles: Preheat a waffle iron. Whip the egg whites with an electric hand mixer until stiff peaks form, and then reserve for a later use.
Whisk the flour, sugar, baking powder, cinnamon and salt together in a large bowl. In a separate bowl, whisk together the milk, vanilla, butter and egg yolks until combined. Pour the milk mixture into the flour mixture and stir gently until the batter is just combined with some small lumps. Fold in the egg whites (there will still be some lumps).
Cook the waffles in the waffle iron according to the manufacturer's instructions, about 3/4 cup batter per waffle. Transfer the waffles to a cutting board and cut each waffle into quarters.
Place the maple syrup in a small saucepot and throw in the rosemary sprigs. Warm over medium-low heat for 5 to 10 minutes, then remove the rosemary.
Arrange the waffle bites on a platter. Drizzle the waffles with a little syrup and top each bite with a chicken chunk. Serve with strawberries to garnish on the plate.