Crack and peel each hard boiled egg and then slice them in half. Place the yolks in a medium mixing bowl along with the mayo and sriracha. Blend well with a fork if you plan to spoon the filling into the egg whites. If planning to use a pastry bag and star tip to fill the egg whites, it works best to use a blender to get the filling as smooth as possible.
In a pan over medium to medium-high heat, melt the butter. Add panko, garlic powder, and salt. Stir to combine. Saute until bread crumbs are fragrant and lightly browned. Remove garlic toast crumb topping to plate to cool.
While bread crumbs are cooling, fill egg whites with sriracha filling using either a spoon or a pastry bag fitted with a star tip. Top with a sprinkling of garlic toast crumb topping, black pepper, and cilantro.
Serve immediately. These can be prepared many hours before serving, but don't add the garlic toast crumb topping until right before serving, to prevent the topping from getting soggy.
