Combine rhubarb, water, and 1 ½ tablespoon sugar into a medium saucepan and bring to a boil, stirring regularly.
Reduce heat, simmer and cook uncovered until tender for approximately 8-10 minutes. Remove from heat, then pour into a small bowl and let cool.
Combine remaining 1 ½ tablespoon sugar and frozen strawberries in an immersion blender or food processor. Blend until pureed. Stir into rhubarb mix.
Fold in vegan whipped cream, then portion into two dessert cups.
Garnish with sliced strawberries and refrigerate for 2-3 hours before servings.