In a small bowl, dissolve yeast in warm water. Let stand until creamy, about 10 minutes.
In a large bowl, mix together flour, baking powder, baking soda, sugar and salt. Make a well in center. Add yeast mixture, eggs, buttermilk and vegetable oil; stir until smooth.
Spray preheated waffle iron with non-stick cooking spray. Pour 1/4 cup batter onto hot waffle iron. Cook until golden brown, about 3 minutes. Serve hot.