In a large mixer bowl, whisk together 2 and 1/2 cups Manhattan Blend and the yeast. Mix together the non-dairy milk, sugar and salt. Add to dry mixture in bowl along with the egg and extract. Using the paddle attachment, mix all ingredients on low speed until combined and then mix on high speed for three minutes.

Lightly flour your work surface with Manhattan Blend or white rice flour and shape the dough into a ball. Cover with plastic wrap and stick in the fridge for 20 minutes to firm up dough and make it easier to roll out.

Take the dough out of the refrigerator to begin the “rolling and folding” process. Flour a work surface with Manhattan Blend. The dough will be sticky, so make sure you have flour nearby as you roll and fold. Using the palm of your hands, gently flatten the dough into a small square. On your floured work surface, use a non-stick rolling pin to roll dough to about a 14-inch square. Place the chilled butter sheet on one half of the dough and fold the other side over it. Press the edges of the dough to seal the butter inside.

Turn your dough 90 degrees, sprinkle the top of the dough with more flour and roll out to about a 20- × 12-inch rectangle. You may have to continue to lightly flour the counter as you are rolling. Fold the dough into thirds as if it were a business letter. Turn 90 degrees and roll again to about 20 × 12 inches. Then, fold again into a business letter. You’ll repeat rolling and folding one more time for a total of three times. (If the dough gets too soft or too much butter oozes out between turns, cover and refrigerate for 10–15 minutes between rolling.)

Wrap dough in plastic and refrigerate for 30 minutes or up to 24 hours.

Begin by creating a “butter sheet.” In the bowl of a stand mixer with the paddle attachment, blend margarine and 1/3 cup Manhattan Blend together well. Using a pallet knife for spreading, spread out onto a sheet of Gefen Parchment or wax paper into a rectangular shape approximately 12 x 6 inches, trying to keep the thickness as even as possible. If the margarine gets stuck to your knife, dip your pallet knife in hot water to make mixture easier to spread. Cover the rectangular butter sheet with another sheet of wax paper and refrigerate for 30 minutes, until the sheet is completely firm.

Preheat oven to 350 degrees Fahrenheit. Lightly grease a baking pan with non-stick cooking spray or line with Gefen Parchment Paper.

Unfold your gluten free Danish dough and roll it into a sheet about two inches thick.  Place the dough sheet onto the prepared pan.

Spread mustard and/or bbq sauce over pastry sheet.  Place meats over the pastry sheet in layers: first pastrami, then turkey and corned beef.  Roll dough up to look like a jelly roll and place seam-side down on the pan.  Brush around the entire surface of the dough with beaten egg.  Sprinkle with sesame seeds.

Bake for 45 minutes to 1 hour, until the outer pastry has slightly browned and some of the sauces from the center have leaked out and are crispy.  Let cool for 10 minutes and slice into 8–10 pieces.