In a shallow bowl or a small plate, combine the ginger powder and sugar.
Swipe cocktail glass with the lemon. Dip and swirl the rim of the glass in the ginger sugar until coated. Add ice to the glass.
In a shaker, combine blueberry jam, pineapple juice, lemon juice, and rum. Add ice and shake until frosty cold. Strain into glass. Top with ginger beer and garnish with fresh blueberries.