1. Preheat the oven to 350F.
2. In a mixer, beat the butter and sugar together for 4 minutes.
3. Add the whole egg and vanilla, mix and add the milk.
4. Add the flour mixture previously mixed with the baking powder, bicarbonate, and salt.
5. Transfer the preparation to a pastry bag with a simple tip.
6. On a baking sheet lined with parchment paper, pipe small dollops of dough, leaving space between them.
7. Bake for 10 minutes. Let cool on a rack.
8. For the cream: mix the butter with the icing sugar and water. Add the food coloring. Fill the whoopies with cream and sandwich with another.
9. For the glaze: mix the icing sugar and water.
10. Drizzle the glaze over the whoopies and let rest for 5 minutes before serving.