In a small saucepan, add the sugar, water, and jalapenos and simmer on low until the sugar completely dissolves and a thick syrup forms. Remove from heat and let the jalapenos steep for a few minutes (the longer you leave them, the spicier the syrup will be). Discard jalapenos and transfer syrup to a Mason jar until ready to assemble drinks.
Fill a mule cup with crushed iced. Add the simple syrup, vodka, and pineapple juice and give it a quick stir. Top with ginger beer until the cup is full. Garnish with a pineapple wedge and maybe a jalapeno rescued from the simple syrup.