In a large mixing bowl, sprinkle dry yeast and add 1/2 cup of warm water. Stir and let sit.
Meantime, melt to liquid the stick of margarine in microwave.
Stir yeast again and add flour, salt, and sugar. Add margarine when it has melted. Do not stir.
In microwave, heat to warm (not boiling) the 2 cups of milk and then add this to the mixture in the bowl. Now use a whisk to combine all ingredients.
Cover bowl and place out of drafts in a fairly warm location and let sit over night.
In the morning the mixture should have risen to about double the size. Add eggs and baking soda and whisk everything again. Heat up your waffle iron and cover with baking spray. Pour on liquid to just cover the griddle. Close and bake for 6-7 minutes until they are golden brown and some what crispy. Sprinkle lightly with powdered sugar. Serve hot. Great served with fresh peaches or strawberries!
Our nephew taps maple trees and makes his own maple syrup; it is truly a special treat to have butter and homemade syrup to serve on these delicious waffles.