For the Crumble, preheat oven to 375 degrees.
Add brown sugar, granulated sugar, cinnamon and flour to a small to medium sized bowl.
Whisk ingredients together.
Slowly add in melted butter and stir in to combine until small crumbs develop.
Spread crumbs on a baking sheet and bake for 10-15 minutes until crisp and golden.
Remove crumbs and allow to cool to room temperature.
For the Ice Cream, add blackberries to food processor and create puree.
Then push puree through a sieve to remove the seeds.
Next, whisk together the cream, milk, sugar and blackberry puree and cook over low to medium heat until small bubbles begin to form.
Add egg yolks to a small bowl.
Take 1/3 of the mixture out and add to the egg yolks bowl and quickly whisk to temper the eggs. Once they are incorporated, add the egg mixture into the remaining blackberry mixture in the pot continuing to whisk.
Once the mixture can evenly coat the back of a spoon, remove from heat and add vanilla.
Make sure the mixture is well mixed and place in the freezer for a couple of hours.
Churn according to your ice cream manufacturer's instructions.
After churning, alternate placing the ice cream mixture and crumbles in a freezer safe container. Freeze for at least 4-5 hours before enjoying.