In a cocktail shaker, muddle two fresh berries. Add the lemonade, simple syrup, vodka, jam and some ice. Put the lid onto the shaker and shake. Shake some more! (You need to distribute the jam.)

Add some ice to a new jam jar and strain in the cocktail. (Discard solids in the shaker.) Top off with a splash of club soda. Garnish with some mint and a few berries if you wish. Serve.

Note: Simple syrup is just a boiled solution made of equal parts water and sugar. It needs to be made ahead of time and allowed to cool before using. In a small saucepan, combine at least 1 cup water and 1 cup sugar. Bring to a boil to dissolve the sugar, stirring occasionally. Turn off the heat and let mixture cool completely before making cocktails.