For the profiterole cream: 

1. Add 1.5 cups of granulated sugar and 2.5 cups of milk to the sauce pot.
2. Then add 1 egg and 3 tablespoons of flour and cook over medium heat.
3. Add 1 packet of vanillin to the thickened profiterol cream and mix again.
4. Remove the profiterole cream from the stove and cool it at room temperature. When the cream cools down, put it in a piping bag and refrigerate for 1 hour.

For the profiterole dough: 

1. Boil 125 grams of margarine and 1 cup of water in a pot.
2. Add 1 cup of flour to it and stir to prevent lumps.
3. When the dough comes together, remove it from the stove and let it rest at room temperature for about 15 minutes.
4. Add three eggs to the dough, one by one.
5. When the dough is completely mixed with the eggs, let it rest for another 15 minutes.
6. Take 1 teaspoon of the dough and place it on a baking sheet lined with baking paper. Keep a space between them.
7. Bake the profiterole dough in a preheated 180-degree oven for 40 minutes.
8. When the profiterole dough is cooked, let it rest at room temperature for 10 minutes.
9. Make small holes in the bottom of the profiterole dough with a knife.
10. Squeeze the prepared profiterole cream through this hole to fill it.

For the chocolate sauce:

1. Crush the dark chocolate into small pieces.
2. Mix the cream and dark chocolate in a small saucepan until melted.
3. Place the filled profiteroles on top of each other.
4. Pour the chocolate sauce you prepared over the profiteroles. Bon appetit.