Preheat the oven to 350 degrees Fahrenheit. Lightly grease a 9-x-5-inch baking dish.
Then, in a large mixing bowl, mix eggs, oil, milk, and vanilla together.
In a separate medium bowl, blend flour, sugar, baking powder,cinnamon and salt.
Then, all at once, add the dry ingredients to the wet ingredients and mix well until smooth.
Now, in a separate bowl, take washed blueberries, dry them, and coat them in a light layer of flour. Then fold the blueberries into the batter.
Pour half of the batter into the prepared baking dish.
In a medium bowl, combine brown sugar and cinnamon and mix well.
Sprinkle half of the cinnamon sugar on top of the batter. Top with the remaining batter by carefully pouring it over the cinnamon sugar layer. Then top with the remaining cinnamon sugar mixture and streusel mixture.
Drizzle the 1 tbsp melted butter over the top, using more or less as desired.
Bake for 35–40 minutes.
While the cake is baking, mix together confectioners sugar, tea, vanilla, cinnamon, and nutmeg to make the chai glaze. Chill while the cake bakes.
Once the cake is baked, pull it out and drizzle the chai glaze over the top. Serve warm!