Creating the moist and flavorful Black Velvet Cake with Blackberry Compote can be accomplished through these straightforward steps:

1. Preheat Oven: Begin by preheating your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.
2. Mix Dry Ingredients: In a large mixing bowl, combine the flour, granulated sugar, cocoa powder, baking soda, baking powder, and salt.
3. Combine Wet Ingredients: In another bowl, whisk together the buttermilk, vegetable oil, eggs, and vanilla extract until well combined.
4. Mix Together: Pour the wet mixture into the bowl with the dry ingredients. Mix until just combined.
5. Add Hot Water: Gradually stir in the hot water, ensuring the batter is smooth and well mixed. It will be thin, which is normal.
6. Divide Batter: Evenly distribute the batter between the prepared cake pans.
7. Bake: Place the pans in the preheated oven. Bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
8. Cool Cakes: Once done, remove the cakes from the oven and let them cool in the pans for 10-15 minutes before transferring to wire racks to cool completely.
9. Prepare Blackberry Compote: While the cakes are cooling, add the blackberries, lemon juice, and powdered sugar to a saucepan over medium heat. Cook until the berries break down, about 5-7 minutes. Remove from heat and let it cool slightly.
10. Assemble the Cake: Place one cake layer on a serving platter. Spread a layer of blackberry compote on top. Add the second cake layer and repeat with the compote.
11. Serve: Optional; top with whipped cream for added indulgence.

These steps will guide you not just in creating an exceptional dessert, but also in enjoying the process of baking!