In a large saucepan or bowl, combine the chopped fresh strawberries, granulated sugar, and lemon juice. Place over medium heat for 2 to 3 minutes to start softening the fruit.

Make a slurry with all-purpose flour and 1 tablespoon of water, then stir into the strawberry mixture and continue cooking for another 1 to 2 minutes until thickened. Remove from heat and set aside to cool.

In a small bowl, combine all-purpose flour, granulated sugar, melted vegan butter, and ground cinnamon. Mix until crumbly and chill in the fridge.

Preheat the oven to 180°C (355°F) and line an 8-inch square baking pan with parchment paper.

In a large bowl, whisk together flour, sugar, baking powder, and salt. Add dairy-free yogurt, dairy-free milk, oil, apple cider vinegar (if using), and vanilla extract. Whisk until combined.

Pour the batter into the prepared pan, smooth the top, then spoon the cooled strawberry layer over it. Sprinkle the chilled crumb topping on top.

Bake for 1 hour to 1 hour and 5 minutes. Tent with aluminum foil if browning too quickly. Check doneness with a toothpick.

Allow the cake to cool in the pan for about 30 minutes. Lift out using the parchment paper and transfer to a wire rack to cool completely. Slice into 16 portions.