Prepare 1 cup of strong coffee. In a saucepan, place the sweetener and a little water (about 3-4 tablespoons). Bring to a boil, stirring constantly. Remove from heat as soon as the sweetener dissolves. Set aside to cool.

In a small bowl, place a few drops of black food coloring and 1 teaspoon of warm water. Mix.

In another bowl, place the tapioca starch. Pour the coloring mixed with water. Stir and knead with a spoon until combined. If necessary, add a little more warm water (this depends on the type of starch - sometimes you need several times more water than indicated, the important thing is to obtain a sticky mass with a consistency similar to modeling clay). Then, knead the dough until smooth with your hands.

Divide the dough into several parts and form a thin roll from each. Cut each roll into small pieces (about 0.5-1 cm). Try to make them all equal in size and able to pass through the thick straw you will use to drink the coffee. Shape each piece into a ball.

In a saucepan, bring about 2 cups of water to a boil. Drop the tapioca balls into the boiling water and cook for about 10-15 minutes or longer, depending on the desired consistency. The balls should increase in size and darken during cooking. Then remove the pot from the heat and let it stand for a few minutes. The balls should shrink a bit.

Pour the coffee (without grounds) into a tall glass, add the milk and sweet syrup. Stir and add the drained tapioca pearls and optionally crushed ice cubes.