For the Coffee Namelaka:
In a small container, combine the cream and the coffee and steep, refrigerated, for 24 hours. Strain and rescale cream back to 240 grams. Melt chocolate over a water bath until it reaches 35°C. In a small saucepot, combine milk, glucose, and gelatin and heat to 85°C. Emulsify hot milk mixture into melted chocolate. Add cold cream and emulsify with an immersion blender. Crystallize in refrigerator for 12 hours. Add to a piping bag fitted with a #805 tip.
For the Choux Crust:
In the bowl of a stand mixer with the paddle attachment, combine bread flour,sugar, and salt. Add cold butter and mix on medium-low until fully incorporated and homogenous. Sheet dough between 2 silicone baking mats to a thickness of 2½ millimeters. Score in ¾-inch wide strips and reserve in the freezer.
For the Pâte à Choux:
Preheat oven to 450°F. In a medium saucepot, combine water, milk powder, and butter and bring to a boil over high heat. Add flour and salt all at once and cook, stirring constantly, until mixture forms a cohesive lump and pulls from the sides of the pot. Transfer dough to the bowl of a stand mixer with the paddle attachment and mix on low speed. Add eggs one at a time, scraping bowl and paddle as necessary between additions to obtain a smooth, consistent dough.
Fill a pastry bag fitted with an #805 round tip with choux paste and pipe long tubes onto a baking sheet lined with a silicone baking mat. Brush with egg wash, top with a frozen strip of Choux Crust, and freeze. Preheat oven to 450°F. Once frozen, cut long tubes to 4½-inch increments. Transfer éclairs to a perforated baking sheet lined with a perforated silicone baking mat, place in oven and turn oven off. Let éclairs rise for 10 minutes in the ambient heat; then set oven to 325°F, open vents, and continue to cook until golden brown and dry.
For the Coffee Marmalade:
In a small saucepot, combine glucose and sugar and cook to a dark caramel. Deglaze with cream, and continue cooking until mixture reaches 106°C. Remove from heat and cool to 35°C. With an immersion blender, blend in butter. Chill.
For the Caramelized Cocoa Nibs:
In a medium saucepot, combine sugar and cocoa nibs. Cook over medium heat, stirring constantly, until sugar caramelizes. Add cocoa butter, stir to coat coat nibs, roll the mixture into a thin layer between two silicone baking mats, and cool. Once hardened, break into small pieces and store in an airtight container.
To Assemble and Serve:
Cut Pâte à Choux in half horizontally. Pipe a line of Coffee Marmalade down the length of each éclair. Top marmalade with pieces of Caramelized Cocoa Nibs. Pipe a tube of Coffee Namelaka on top of the marmalade and nibs. Put the top of the choux back in place and press firmly to close. Pipe three small dots of Coffee Namelaka on top of the éclair and use them to affix a rectangle of tempered chocolate.