Put the flax seeds and water in a bowl, set aside so they thicken.
Preheat the oven to 360°F and cover a 20×10 inch baking pan with a baking sheet.
Melt the vegan butter in the microwave and then add the sugar, flax seeds with water and vanilla extract, until smooth.
Put the previous mixture in a bowl and sieve the flour, cocoa powder and baking powder over it. Mix with a spatula. Add half the chocolate to the mixture and incorporate. Move to the mold and cover with the remaining chocolate. Put in the oven and cook for about 35 minutes.
Remove from the heat and allow to cool for at least 15 minutes before cutting or serving.
Whip the cream to stiff peaks and put it in a pastry bag.
To serve, cut the brownie into 16 equal pieces, make a circle with the pastry bag and place a strawberry on it. Top with a cream dot on top of each strawberry.
