In a small bowl combine the warm water, sugar and yeast. Stir to combine and then set aside to allow it to foam. Then add the milk, ground flax seeds, corn starch, and water. Mix well and set aside.
Pour the salt, flour and sliced margarine in the bowl of a food processor. Pulse for several seconds and then use a spatula to push down any ingredients that moved its way up the bowl. Repeat these several times until the mixture has combined and resembles crumbles the size of peas.
Next pour the crumbly flour mixture and the yeast mixture into a large bowl and gently stir the two together until just barely combined. You want to see large flecks of the margarine showing through. This is what creates the best, flaky pastries! Tear off a piece of plastic wrap and lay it on the counter and then turn the dough on that piece of plastic wrap. Wrap up the dough and place it in the fridge to chill out for at least four hours or more.
After the dough has thoroughly chilled, it's time for the next step in the process, referred to as "rolling and folding". Pour a light layer of flour over a work surface. Keep some extra flour nearby because the dough is sticky and you're going to be using your hands with this. Use a floured rolling pin to flatten the dough. Roll it out into the shape of a rectangle 15" long. Next fold one end of the rectangle shaped dough toward you and fold the other end over that (like you're folding a letter). Now repeat that process by rolling it out into a 15" rectangle and fold both ends over like a letter. Repeat that process one more time, but after this last time, wrap it in plastic wrap and place it in the fridge to chill out again for at least 30 minutes.
While the dough is chilling you can prepare your Blueberry Filling. Stir together the corn starch and water in a small bowl. Place the blueberries and sugar in a microwave safe bowl. Pour the corn starch mixture over the sugared berries and stir gently. Place it in the microwave and heat it for one minute intervals, stirring gently (and carefully) between each. Continue this until the sauce has thickened. Set aside to cool.
Once the dough has chilled again, remove from the fridge and cut it in half. Return one half of the dough to the plastic wrap and put it back in the fridge. With the remaining half, place it on a lightly floured surface and roll it out into the shape of a 12X6 rectangle.
Next, use a knife to slice off the two corners of the rectangle farthest away from you and cut in two small triangles on the other end (see the photo below).
Spread half of the blueberry filling in the center of dough before cutting slanted strips along both sides. (I highly recommend checking out the visual guides on Sally's Baking Addiction site for her Braided Danish recipe). Beginning at the bottom, "braid" the dough, sealing the piece at the bottom. Very carefully transfer the braid to a baking pan that has been covered with parchment paper. Set aside.
At this point begin heating your oven to 400F.
Next, repeat Step #8 with the second half of the dough. When you're done, place that braid on a baking pan covered with parchment paper as well.
Fold the bottom end up to "seal" the filling in and allow the braid to rest for 15-20 minutes as you preheat your oven. Repeat with the second half of the dough and the rest of the filling.
Prepare the pastry coating by stirring together 1 tablespoon of melted margarine and 1 tablespoon soy milk. Brush the top of both pastries with the pastry coating.
Place the braids in the oven and bake for approximately 15 minutes or until that pastry coating has turned golden brown.
When done, remove them from the oven and cool for several minutes.
While the danish braids are cooling, prepare the Mocha Glaze by stirring together the powdered sugar, mocha extract and the soy milk. Stir until combined.
Allow to cool for at least 10 minutes. Drizzle the top of both danishes with the glaze, reserving some for individual slices too. Serve slices slightly warm.