To a food processor (or small-capacity blender, see Note 2), add the following ingredients: balsamic vinegar, Dijon mustard, garlic, shallot, salt, a generous amount of black pepper, and 1 ½ teaspoons maple syrup or sugar.
Blend until smooth, scraping down the sides as needed. With the motor running, stream in the olive oil and blend until the olive oil has emulsified the dressing. Taste, adding more maple syrup for sweetness and season with salt or pepper as needed.
Store in a sealed jar in the fridge for 10 to 14 days. If the oil solidifies in the fridge, simply add the sealed jar to a bowl of hot water and wait until the oil liquefies. Then whisk again (or shake the jar vigorously) to re-emulsify.