In a medium skillet, melt 1 Tblsp. butter over medium heat. Add the chopped onions, honey, and 1/2 tsp. salt. Cook for around 10-15 min. or until tender and golden. cool.
While the onions are cooling pre heat oven to 325 degrees. lightly grease a cookie sheet or a silpat works great! set aside.
In a large bowl combine flour, sugar, baking powder, and the remaining 1 tsp. salt. Stir in the cooled onion mixture and grated lemon if using. Make a well in the center of the flour and onion mixture. Place eggs and egg yolks in the well and stir into the flour mixture. Melt remaining 6 Tblsp butter and add to mixture. Stir until combined. (It will be crumbly) Using your hands, kneed the dough for approx. 5 minutes until it comes together.
Divide the dough into 2 equal portions. On a lightly floured surface, shape each portion into a 14" log. Place them on your prepared cookie sheet, flatten the logs slightly. Bake about 25 minutes or until golden and firm. Cool for approx. 15 min.
Transfer logs to a cutting board. Use a serrated knife to cut each log diagonally into 1/2" slices. Place slices cut side down, on cookie sheet. Bake for 7-10 min. Turn slices over and bake for 7-10 minutes more or until golden and crispy. Cool.