Preheat the oven to 180°C (356°F) and line a 12 cup muffin pan with cupcake liners and set it aside.
In a small bowl, combine the dairy-free milk and vinegar. Stir well and set aside for a few minutes to curdle. This will create a vegan buttermilk substitute.
In a separate mixing bowl, whisk together the plain flour, freeze dried strawberry powder, baking powder, and bicarbonate of soda.
Into a large mixing bowl, add the vanilla extract, canola oil, and sugar to the bowl and whisk to combine. Gradually add the dry ingredients, alternating each addition with the milk mixture until just combined. Be careful not to overmix; a few lumps are okay. Gently fold in the chopped fresh strawberries.
Spoon the batter into the prepared cupcake liners, filling each one about two-thirds full.
Place the muffin tray in the preheated oven and bake for approximately 18-20 minutes, or until a toothpick inserted into the centre of a cupcake comes out clean.
Once baked, remove the cupcakes from the oven and allow them to cool in the muffin tin for 5 minutes before transferring to a wire rack to cool completely.
Make the strawberry buttercream. Using a hand mixer or a stand mixer with the paddle attachment fitted, beat dairy-free butter and vanilla for 1-2 minutes until creamy. Add in 2 cups of icing sugar and beat on medium until combined. Add in an additional cup of icing sugar and the freeze dried strawberry powder and continue to mix. As mixture thickens, add in dairy free milk a little at a time until you reach a thick, creamy consistency. If the frosting is too thin, add in an extra ½-1 cup of icing sugar, and if it’s too thick, add a little bit more dairy free milk. Finally add a pinch of salt to taste and continue to mix until super creamy.
Add the buttercream to a piping bag with a piping tip attached and pipe swirls of frosting onto the cooled cupcakes. Top with extra fresh strawberries if desired.