01 -  Preheat oven to 400°F. Line a 12-cup muffin tin with paper liners or lightly grease each cup. 
 02 -  Whisk the all-purpose flour, baking powder, baking soda, salt, and granulated sugar together in a large mixing bowl until thoroughly blended. 
 03 -  Add shredded cheddar cheese and finely diced jalapeños to the flour mixture, tossing to coat evenly. 
 04 -  In a separate bowl, whisk together the brewed sweet tea, buttermilk, melted butter, and egg until uniform. 
 05 -  Pour wet ingredients into the dry mixture. Stir gently with a spatula just until incorporated. Avoid overmixing to maintain muffin tenderness. 
 06 -  Divide batter evenly among muffin cups, filling each approximately three-quarters full. 
 07 -  Bake in preheated oven for 18–20 minutes until muffin tops are golden and a toothpick inserted into the center emerges clean. 
 08 -  Cool muffins in the pan for five minutes, then transfer to a wire rack to cool slightly before serving.