Preheat oven to 180°C and line your muffin tin with paper liners.
In a large bowl, whisk flour, baking powder, baking soda, salt, and sugar.
In another bowl, mix plant-based milk, melted coconut oil, vinegar, and vanilla.
Combine wet and dry ingredients gently until just mixed — don’t over-stir.
Fold in blueberries, coating them evenly in the batter.
Scoop the batter into the muffin cups, filling them about ¾ full.
For the streusel, mix flour, sugar, coconut oil, and cinnamon with your fingers until crumbly.
Sprinkle streusel generously over each muffin.
Bake for 20–25 minutes, or until golden and a toothpick comes out clean.
Cool slightly before eating (if you can wait that long).