Overnight Yeasted Whole Wheat Waffles

0 Heat milk on the stovetop or in the microwave until it is warm (but not hot) to the touch.
1 In a large mixing bowl, combine melted butter, milk, sugar, and salt. (Note: Important - use a very large mixing bowl as the batter will expand up to 3x its original volume as it rises.)
2 Add flour, yeast, and baking soda all at once and stir until smooth. 
3 Cover the bowl with plastic wrap or a lid. 
4 Leave batter to rise on the counter for 2 hours or transfer to the refrigerator for up to 12 hours. 
5 When you’re ready to make the waffles, heat a waffle iron according to manufacturer's instructions.
6 Spray the waffle iron with nonstick cooking spray or lightly grease with melted butter.
7 Spoon the waffle batter into the iron, being careful not to deflate it too much (you don't want to lose all of the bubbles in the batter that will give the waffles their light texture). 
8 Cook waffles until golden brown on both sides.
9 Serve immediately with butter, syrup, and / or fresh berries.