Preheat your oven to 350°F and line an 8×8 baking sheet with parchment paper.
In a large bowl, mix together the almond milk, coconut sugar, melted vegan butter, and vanilla extract. Then, gently fold in the gluten-free flour, baking powder, salt, and cinnamon until well combined.
Peel and dice the green apple, then add it to the batter and mix until evenly distributed.
Pour the batter into the prepared baking dish.
Now, let’s make the streusel topping! Combine the vegan butter, brown sugar, salt, and gluten-free flour until crumbly. Sprinkle this mixture evenly over the batter in the baking dish.
Bake for 30-35 minutes, or until a toothpick inserted into the center comes out clean.
Once the coffee cake is done baking, drizzle it with the icing.
Serve warm alongside a steaming cup of coffee for the perfect start to your day!