In a large mixing bowl, combine equal parts all-purpose and bread flour, active yeast, sugar, salt, milk, and a beaten egg. Mix until smooth, about 5-7 minutes. Cover and refrigerate for 1 hour.

Spread softened butter into a rectangle (8x10 inches) on parchment paper. Fold and refrigerate for 30-45 minutes.

Roll out the dough into a rectangle (12x24 inches). Place the butter envelope on the lower two-thirds of the dough, fold top third over the butter, and seal edges. Roll out and fold into thirds, chilling for 30 minutes after each fold.

Mix melted butter, sugar, salt, orange zest, and Earl Grey tea leaves in a medium bowl until combined. Set aside.

Roll out the laminated dough into a large rectangle (12x24 inches). Spread filling over surface, leaving a border. Roll tightly from one long side into a log shape.

Slice the rolled dough into 12-15 pieces. Arrange cut side up in a greased muffin tin. Cover and let rise in a warm place for 1-2 hours until puffed.

Preheat oven to 400°F (200°C). Brush tops with beaten egg and bake for 30-40 minutes until golden brown. Cool on a wire rack before rolling in reserved sugar.