Start by preparing the fruit: Dice the apples into small cubes (make sure to peel the skin), use a melon baller to get one cup of melon and watermelon (if you don't have one dice into cubes), and cut the grapes in half.
In a large bowl, marinate the raspberries, apple, white melon, and grapes, along with the 2 tablespoon of sugar and ¼ cup of brandy (if using). Marinate for at least 20 minutes, but preferably 1 hour.
In the meantime, make a simple syrup by heating the ⅓ cup of water and ⅓ cup of sugar in a small saucepan until the sugar is totally dissolved and the mixture starts to simmer. Remove from the heat and let cool.
Add the bottle of white wine and the pineapple juice to the marinated fruit. Taste for sweetness (depending on the fruit used it may or may not need the simple syrup). Adjust with simple syrup if necessary.
Prepare a large glass with ice cubes, some fresh blueberries, and fresh watermelon. Pour the sangria mixture over the glass until ⅔ full. Top off with cold cava. Stir ever so slightly to make sure everything is mixed, but not enough to break the bubbles in the cava.
Enjoy!