This brioche Nanterre can be well enjoyed on its own because of its buttery and rich flavor. Just add a cup of coffee for a complete indulgence!
In the bowl of heavy-duty mixer, Add the yeast, milk, egg and 1 cup all-purpose flour. Mix with a rubber spatula just until combined. Sprinkle the remaining 1 cup of flour over the top as if to cover the mixture. Let this stand for about 40-45 minutes. There will be cracks on the flour surface at this point.
Add the sugar, salt, eggs and 1 cup of flour to the bowl with the yeast mixture. Using a dough hook, run the heavy-duty mixer on low speed briefly until the mixture is just about incorporated. Add the remaining half cup of flour and run the mixer at medium speed. Continue to beat, scraping the bowl as needed, for about 15-20 minutes. You will know when the dough is ready if it is coming together in the center of the bowl, and also attaching itself into the dough hook. You should see the dough slapping the sides of the bowl, like it is almost violently throwing itself to the sides white it still clinging and rotating with the dough hook. You should also hear the slapping sounds. ( If you don't see the slapping action after ten minutes into the mixing, sprinkle about 2 -3 tbsp of flour to the bowl. Continue to beat until you reach the slapping stage, giving the dough a total of about 15-20 minutes in the mixer ).
With the mixer still running, add the butter bit by bit. Make sure that the butter is in room temperature, soft but not oily. (It helps to enclose the butter inside a wax paper, press it down using your thumb or beat it with a rolling pin to give it a malleable consistency) When you add the butter, the dough will fall apart again for a moment. Continue to beat until you hear the slapping sounds again. This should take about 5 minutes or so. The dough is now, once again, clinging together in the center and in the dough hook with the slapping sound. The dough is sticky but shiny at this point.
Shape the dough into a ball and place it in a bowl. Cover it with a clean kitchen towel and let it rise for 2 hours, or until doubled in bulk. After rising, gently deflate the dough by lifting it along the edges, section by section, until the dough falls back down in the bowl deflated. Cover the bowl with a plastic wrap. Chill in the fridge for at least 6 hours to overnight. During this stage, the dough will double in bulk again.
Take the dough out of the fridge. Divide it into 2 equal portions, Divide each portion into 8 portions, giving you a total of 16 portions. Grease two 9x5 inch loaf pans. Shape each of the dough portions into a smooth ball. Arrange 8 balls in each loaf pan, 2 balls side by side, for a total of four rows in each pan. Brush the balls with beaten egg and cover loosely with a clean kitchen towel. Let the dough rise for 2 hours at room temperature.
Preheat oven to 350 F. Brush the tops of the dough lightly with egg wash once more and bake at 350 F for 35-45 minutes. Cover the pans loosely with foil during the last ten minutes to avoid over-browning. The pastry is done once a thermometer inserted into the crumbs reads 200 F.