Crisp the bacon: Cook bacon in a skillet over medium heat until crispy, about 8-10 minutes, flipping once. Transfer to a paper towel-lined plate to drain, reserving the fat in the pan. Once cool, chop the bacon.
Sauté the onion: In the same pan with the reserved bacon fat, add the diced onion and sauté over medium heat until softened and lightly golden, about 4-5 minutes.
Combine bacon and onion: Add the chopped bacon back to the pan with the onions. Stir in the onion and garlic seasoning blend, kosher salt, and black pepper.
Add the maple syrup: Pour in the maple syrup and stir to coat everything. Simmer for 2-3 minutes until slightly thickened and jammy. Remove from heat and let cool slightly.
Hard boil the eggs: Place eggs in a single layer in a saucepan and cover with cold water by an inch. Bring to a boil, then cover, remove from heat, and let sit for 11 minutes.
Cool and peel: Transfer eggs to an ice bath for 5 minutes to stop cooking, then peel under cool running water.
Make the filling: Slice eggs in half lengthwise and pop yolks into a bowl. Mash yolks smooth, then mix in mayonnaise, Dijon mustard, chives, salt, and pepper until creamy.
Fill the eggs: Spoon or pipe the yolk mixture back into the egg white halves.
Top and serve: Top each egg with a spoonful of warm maple bacon jam. Chill 15-20 minutes if needed, then serve.