Preheat the oven to 350 degrees F. Line 12 muffin tins with paper liners or spray the pan with a non-stick spray.
In a small saucepan, bring the buttermilk to a gentle simmer over medium to low heat. Remove from heat. Add the tea bags and steep for about 20 minutes. Discard the tea bags.
For the streusel, add the flour, brown sugar, cinnamon, and butter to a small bowl. Mix together with your hands until you have a crumbly mixture. Alternatively, you may place the ingredients in a food processor and pulse 4-5 times or until the mixture is crumbly/sandy. Set aside.
Whisk together the butter, maple syrup, vanilla, steeped buttermilk, greek yogurt, and eggs in a large mixing bowl until smooth. Add the flour, baking powder, baking soda, cinnamon, and salt. Fold the ingredients together until just combined. Do not over-mix. Gently fold in the blueberries and blueberry jam, being careful not to over mix.
Divide the batter among the prepared tins. Evenly sprinkle the streusel over the batter. Transfer to the oven bake for 30 minutes or until a toothpick comes out clean. Serve with a pat of butter.