I used to make these for my children when they were little they were a special after school treat with peanut butter on them with sliced apples....We were a military family and didn't have a lot of money so I made home goodies all the time which was a special treat for the family...
In large bowl, dissolve in warm water, let stand till foamy, 5 min.
In med saucepan over med heat, heat milk till bubbles appear at edges of pan. Remove from heat stir in butter, sugar and salt.
Let milk mixture cool till lukewarm. Using a whisk, beat in egg till well blended. Add to yeast mixture. Add 2C of flour and beat with wooden spoon till smooth (3 min). Add 1 1/2C of flour and beat till dough is moderately soft (2-3 min) longer. If the dough is too soft, add more flour a little at a time.
Turn dough out on to lightly floured board and knead till smooth and elastic, approx (5-6 min). Shape into ball, put into lightly oiled bowl, and coat with spray. Cover bowl with plastic wrap and a warm damp kitchen towel, to let dough rise, set in warm place I prefer microwave for it is a controlled inviroment. Till doubled in size, about 1 hour, you will need to check the towel and re dampen with warm water from time to time...
Punch down dough, recover, let rest (10 min) Meanwhile, preheat oven 450*F. Dust cookie sheet lightly with flour.
Pich off into olive sized large olive sized balls (roll) on floured board lay waxed paper over top. Using pastry roller rollout each ball paper-thin 2" in diam and place on cookie sheet. OPT sprinkle with coarse sea salt. Then prick each cracker with fork to prevent puffing.
Put into oven for 5 min. turn over crackers and back for another 5 min till a golden brown. Puncture any bubbles with fork let cool on sheet....