Preheat oven to 425 degrees F (215 degrees C). Line a large baking sheet with parchment paper.
Rinse the brussels sprouts and dry them thoroughly with paper towels. Chop off the bottom of the brussels sprouts and then chop them in half. There will be many leaves that fall off, but save them! They're the best part.
In a medium bowl, mix the brussels sprouts with 1 tablespoon of olive oil, the maple syrup, and balsamic vinegar. Toss until everything is well incorporated. I like using my hands to rub all the flavor into the sprouts. Spread them on the prepared baking sheet in a single layer. Bake for 20-23 minutes or until the leaves are browned.
Heat a small skillet over medium-high heat. Once the pan is hot, add the remaining tablespoon of olive oil. Pour the chopped onions into the skillet and let it cook until the onions start to turn translucent (about a minute or two). Add the corn, ham, and a pinch of salt and stir everything. Cook for about 3-4 minutes, until the corn starts to turn into a vibrant yellow color.
In another medium bowl, mix the roasted brussels sprouts with the corn and ham. Serve as a side dish.
Refrigerate any leftovers in an airtight container.