Defrost cherries in a sieve.
For the choux pastry, heat milk and 60 ml water with 1 pinch of salt and butter until the butter has melted. Bring to the boil and remove from the stove. Add flour and cocoa at once and mix with a wooden spoon.
Burn the choux pastry, but put the pot back on the stove. Stir over a low heat until the dough comes off the bottom of the pot as a lump and forms a white layer.
Take the pot off the stove. Stir in the eggs one by one with a wooden spoon or the dough hooks of the mixer until the mixture is smooth and shiny.
Line a tray with baking paper. Preheat the oven (electric cooker: 200 °C/circulating air: 175 °C/gas: see manufacturer). Fill dough into a piping bag. Spray thin strips (each approx. 10 cm long) onto the baking tray with a slight gap.
Bake in the oven for approx. 20 minutes without opening the oven door (otherwise the pastry will collapse). Take out, let cool down. Just before serving, cut open with a saw knife or scissors.
Fill with creams.
Pour the dough into the piping bag with the large star-shaped spout. Line a baking tray with baking paper and preheat the oven (electric oven: 200 °C/circulating air: 175 °C/gas: see manufacturer). Spray 10 approx. 3 cm wide strips (each approx. 10 cm long) onto the tray.
Bake in a hot oven for about 25 minutes. Remove and let cool off.
For the cream, whip the cream until stiff and allow the sugar to trickle in. Stir in the kirschwasser. To serve, cut the top of the eclairs lengthwise. Fill the cream into the piping bag with the middle perforated spout.
For example 3⁄4 Spray cream into the eclairs. Spread cherries on top. Add the rest of the cream. Crumble the biscuits coarsely and sprinkle them over the éclairs as crumbles.