Combine the water and yeast and allow to sit for five minutes.
In a large bowl, combine the yeast mixture, butter, sugar and egg. Add the flour, baking powder, and salt and stir with a wooden spoon until just combined and comes together into a ball.
Cover with a towel and allow to rise in a warm place for 30 minutes.
Split the ball of dough into two equal pieces and put one half back in the bowl. Roll out the other half on a floured surface to about 12 inches in diameter.
Cut into 12 equal triangles. Starting with the fat end, roll up each triangle and place in a buttered baking pan. Repeat with the other half of dough.
Cover the baking pan with a towel and let rise for an additional 20-30 minutes. Meanwhile, preheat oven to 375°F.
Bake rolls until golden brown, about 20 minutes. Remove from the oven and then immediately brush with butter.
Rolls will keep in an airtight container for up to 3 days.