Add the cup and tablespoon of milk to a bowl. Whisk in the yeast and sugar.

Sift the flour, baking soda, and salt into the milk and whisk until combined and smooth.

Cover the bowl with plastic wrap and leave in a warm place for 1 hour; the dough should double in size.

Preheat a cast iron non-stick skillet over medium low heat with butter.

Spray 4-3 inch ring molds or cookie cutters with non-stick spray and set them to the skillet.

Do not stir the batter, spoon 1 tablespoon of dough into the rings until half full.

Cook for 6 to 8 minutes or until the bubbles all burst and create holes and the top is no longer shiny.

Using tongs to remove the rings. If they stick, run a knife around the edge.

Use a spatula to flip the crumpets over and brown for 1 minute on the other side.

Serve warm with butter.