Crust

1. Preheat the oven to 160°C
2. In a blender, crunch the speculoos to the consistency of sand. Add the softened butter and mix well to form a paste.
3. Place the dough in the bottom of a removable bottom cake pan, and press using a fork or your hands. Cook for 8 to 10 minutes.
4. Let it cool, then refrigerate until needed.

Dough

1. In a bowl, beat the softened cream cheese for two minutes.
2. Add the sugar, and beat for two more minutes.
3. Add the eggs one by one and mix until homogeneous.
4. Add the vanilla extract, yogurt, and the vanilla extract and beat well until the mixture is completely homogeneous. The quantity of vanilla extract depends on your extract. It can be a few drops if it's concentrate.
5. Wrap the spring form pan up the bottom and sides with a double layer of foil.
6. Pour the mixture in the base. Put inside a bigger container and fill the container with hot water. Bake for about 45 minutes.
7. Check for doneness with a toothpick.
8. When it is cooked and not too brown, turn the oven off and slightly open the door.
9. The pie should cool completely in the oven, so it does not crack.

Icing

1. Add blackberries, sugar and water small saucepan, and heat on low. I like to blend some small part of the blackberries to make it juicier.
2. Stir constantly until mixture reaches the consistency of a candy (opens a path at the bottom of the pan), turn off the heat, and let cool a bit.
3. Once cold, remove the pie from the pan, and cover with the blackberry topping.

Recipe sources [1], [2]