Preheat oven to 375. Lightly grease a baking sheet.
In a large bowl, mix together flour, sugar, baking soda, baking powder and salt.
Add ½ cup butter, 1 cup buttermilk and egg to dry ingredients and mix until combined.
Flour a work surface. Turn out the dough on to the surface and knead briefly.
Shape dough into a round and place on prepared sheet.
Whisk together ¼ cup melted butter with ¼ cup buttermilk.
Brush loaf with buttermilk mixture.
Cut an X in the top of the loaf.
Bake 45 minutes or until toothpick inserted into the middle comes out clean.
Brush with buttermilk mixture every 15 minutes or so while baking.