In a small bowl, sprinkle yeast in the lukewarm water and stir.
1 teaspoon instant yeast, 4 Tablespoons lukewarm water
In another small bowl, add egg, sugar, coffee, salt, brown food color, and vanilla extract. Mix together to moisten dry ingredients
1 small egg, ½ cup granulated sugar, 1 teaspoon strong coffee, ¼ teaspoon salt, 1 teaspoon vanilla extract, 1 teaspoon brown food color
Combine bread flour and cocoa powder in a mixing bowl. Add the yeast, egg mixture, and melted butter and stir with a wooden bowl to form a dough.
1.5 cup bread flour, 3 Tablespoons Dutch-process cocoa powder, 1 Tablespoon unsalted butter
Grease your hands and the surface with some oil and knead the dough until smooth and elastic. Add more oil if too sticky.
Form the dough into a ball and cut it into quarters. Roll each part into a log and cut the dough into 6 equal parts, and shape these into balls. Place the balls on a plate or baking sheet then cover with a tea towel and let it rise for an hour.
In a small pot or deep pan, heat about 3 inches of oil over medium heat. Fry 4-5 balls at a time for about 2-3 minutes turning them 2-3 times in between with a fork or wooden stick.
vegetable oil
Using a spider ladle or slotted spoon, remove the balls from the oil and transfer them to an oil dripping rack to remove excess oil.
While the balls are cooling down, prepare the glaze. In a shallow wide bowl, mix together powdered sugar and water until it forms a glaze. Add vanilla extract and stir until incorporated.
1 cup powdered sugar, 3 Tablespoons water, 1 teaspoon vanilla extract
Once the balls have cooled down, place 3-4 balls in the bowl with glaze and turn them around to fully coat. Take a ball and roll it on the orange streusel, pressing lightly to generously cover all sides.
Transfer coated balls into a tray or plate. You may also double coat with glaze and streusel if you like.