Creating these enchanting rolls is easy when you follow these straightforward steps:

1. Preheat the Oven: Set your oven to 375°F (190°C). Prepare a baking dish by greasing it lightly with cooking spray or butter.

2. Mix Dry Ingredients: In a large bowl, whisk together the flour, granulated sugar, baking powder, and salt until well combined.

3. Add Butter: Cut in the softened butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs.

4. Combine Wet Ingredients: In another bowl, whisk together the milk and egg until thoroughly mixed.

5. Create the Dough: Gradually pour the wet mixture into the dry mixture, stirring until just combined. Do not overmix; some lumps are okay.

6. Form the Dough: Transfer the dough onto a floured surface and gently knead it a few times until smooth. Roll it out into a rectangle, about 1/4 inch thick.

7. Prepare the Filling: In a small bowl, mix the blackberries with brown sugar and cinnamon, spreading the mixture evenly over the dough.

8. Roll It Up: Starting from one long side, tightly roll the dough into a log. Pinch the seams to seal.

9. Slice the Rolls: Cut the log into 10 equal slices and place them cut-side up into the prepared baking dish.

10. Bake: Place in the preheated oven and bake for 25-30 minutes, or until the rolls are golden brown.

11. Cool: After removing from the oven, let the rolls cool in the baking dish for about 15 minutes before glazing.

12. Prepare the Glaze: In a small bowl, whisk together powdered sugar, milk, and vanilla extract until smooth and drizzle consistency is achieved.

13. Glaze the Rolls: Drizzle the glaze over the warm rolls, allowing it to soak in for maximum sweetness.