The night before:

1. Pour 1 750ml bottle of rosé into 2 ice cube trays. Freeze overnight.
2. Make spicy jalapeño simple syrup: Bring 1/2 cup sugar, 1/2 cup water and 1 roughly chopped jalapeño to a boil. Reduce heat to low and let simmer for 10 minutes. Let cool completely before straining. Syrup will keep in the fridge for up to 2 weeks. 

Make spicy watermelon frosé:

1. Add 2 cups cubed watermelon to blender. Blend on high until you have watermelon juice. You can strain it out and then put it back in the blender if you want, but I don't bother.
2. Add 1/4 cup lime or lemon juice, rosé ice cubes and 1/4 cup spicy simple syrup. Blend until combined and thick. If the consistency is too thin, throw in a few ice cubes. If it's too thick, just let it sit for a few minutes (or if you really want, crack open another bottle of rosé and add a splash!). 
3. Taste and add more simple syrup or lime/lemon juice if desired. 
4. Serve frozen (duh)!