Preheat oven to 350°F (176°C).
In a bowl add the vegan butter and sugar and cream together with a hand or stand mixer on a low speed until light and fluffy. About 30 seconds to 1 minute, depending on how soft the vegan butter is. **if using vegan butter in a stick save the wrapper and use it to grease the pan.
Then add the nondairy milk, vanilla and lemon extract. Then mix for about 15 seconds until combined.
Add the zest and juice of 1 lemon.
Scoop about 1 to 2 spoonfuls of flour over your blueberries and toss to coat. This will help them to stay a bit more suspended in the batter. Make sure your blueberries are dry so it coats them evenly. Set them aside.
Then add the baking powder, half of the flour, and half of the vegan sour cream into the bowl. Mix on a low speed for about 30 seconds it will be runny.
Then add the remaining flour and vegan sour cream and mix on a low speed for about 45 seconds or until combined. The batter will be thick.
Gently fold in the blueberries.
Pour into the greased baking pan (either grease with baking spray or the vegan butter paper).
Bake on the middle rack for 50 minutes. Then move up to the top rack for 10 minutes. The cake should be golden on top and a toothpick will come out clean.
Let it cool for about 10 minutes. Then carefully remove it from the pan and place on a dish or wire rack. Cool for about 50 minutes to an hour.
Prepare the glaze by mixing the two ingredients together.
Once the cake has cooled pour it over the cake and garnish with extra blueberries, lemon slices and a sprinkling of powdered sugar.