Preheat your oven to 200 C/ 400 F . Line a baking tray with parchment. To make it easier, draw an outline of the circle in the size you want to pipe on the parchment , and turn it over so you can still see the outline.
In a heavy bottomed saucepan, heat the butter and water until the butter melts and it starts to boil.
Add the flour, sugar and salt and heat on medium low while stirring with a wooden spoon. Keep heating and stirring until a film forms on the bottom of the pan and the mixture forms a smooth ball. This will take about 3-4 minutes.
Take off heat and cool for 3-5 minutes.
Mix in the eggs , one at a time, mixing after each egg until fully incorporated.
Stop mixing when the dough is smooth and holds a peak when touched.
Fill into a pastry bag fitted with a wide round tip or snip off the end to make a 1-2 cm opening.
Pipe a circle along the marked outline and then pipe one more circle on top of that.
Sprinkle the almonds on top and using a pastry brush or spoon , brush milk (or beaten egg) on top and sides. Smoothen any irregularities.
Bake at 200 C/400 F for 15 minutes and then at 180 C/ 350 F for 35-40 minutes. The tops will be well browned. Switch off the oven, but let it rest in the oven with door slightly ajar for 10 minutes.
Cool completely and slice horizontally into two using a sharp knife.
While the pastry is cooling, whip up the cream, coffee and sugar until stiff peaks.
Slice the cooled choux horizontally into two , pipe the whipped cream into bottom half and place the top half on top. Dust with icing sugar to serve.