To create your delicious blackberry dumplings, follow these simple steps:

1. Prepare the Blackberries: In a bowl, combine the fresh blackberries, ½ cup of sugar, lemon juice, and vanilla extract. Gently toss to coat and set aside to marinate for about 10 minutes.

2. Make the Dough: In a separate large mixing bowl, combine the flour, baking powder, salt, and cinnamon (if using). Mix thoroughly.

3. Combine Wet Ingredients: Add the melted butter and milk to the dry ingredients. Stir gently until just combined. Avoid overmixing for fluffy dumplings.

4. Combine Ingredients: In a large pot, add the marinated blackberries and any leftover juices. Pour in 2 cups of water and the remaining ½ cup of sugar. Bring the mixture to a boil over medium heat.

5. Add Dumplings: Reduce the heat to a simmer. Drop spoonfuls of the dough mixture onto the simmering blackberry mixture, ensuring not to overcrowd the pot.

6. Cook the Dumplings: Cover the pot with a lid and allow the dumplings to cook for approximately 12-15 minutes. They should become puffy and cooked through.

7. Check for Doneness: Gently lift the lid and check if the dumplings are firm and have doubled in size. Ensure they are cooked through.

8. Serve Warm: Once done, carefully remove the dumplings with a slotted spoon and serve them warm with some of the blackberry syrup.