Measure out and prepare all the ingredients. Preheat oven to 350F.

Cut off the ends of the zucchini and peel them. Slice the zucchini in half lengthwise and scoop out the seeds with a spoon. Discard the seeds.

Chop the zucchini into small pieces. Add the chopped zucchini into a pan of boiling water for 2-3 minutes. Drain and pat dry.

In a bowl, combine cooked zucchini, blackberries, cinnamon, lemon juice, powdered erythritol, and cream of tartar. Mix until fully combined.

In another bowl, combine almond flour, erythritol, and vanilla extract. Press the butter into the other ingredients using a fork to make a crumble like consistency.

In an oven-safe skillet, add the blackberry zucchini filling to the bottom of the pan. Then sprinkle with the crumble topping. Bake for 30-40 minutes, or until topping is golden brown.

In a separate bowl, whip the cream until desired consistency is reached. Top the crumble with whipped cream and enjoy warm!