Use a paring knife to carefully remove peel from oranges (try to avoid cutting the white pith, you only want the orange zest) and place in a medium container. Juice oranges and reserve juice in fridge.
Sprinkle sugar over orange peel, seal container, and shake several times to infuse peel with sugar. Let sugar mixture sit at room temperature overnight or at least 8 hours (up to 24)
The next day, stir 1/4 cup water into sugar mixture until sugar is dissolved. Strain sugar mixture through a fine-mesh sieve into a medium bowl. Remove a few peels from sieve and finely mince into 1 tablespoons worth of peel. Add to orange sugar syrup and discard remaining peels.
Whisk 1/4 cup reserved orange juice, rice vinegar, soy sauce, and cornstarch-water mixture into orange sugar syrup until smooth. Set aside for a moment.
In a medium skillet over medium-high heat, heat oil until shimmery. Add ginger, garlic, and jalapeno and saute 1-2 minutes until just fragrant. Reduce heat to medium and pour sauce mixture into pan. Cook stirring occasionally until sauce is bubbly and thickened. Cover sauce and keep warm on low.