Make Pastry Cream: Heat coconut milk, half the sugar, and vanilla in a saucepan until simmering. In a bowl, whisk yolks, remaining sugar, and cornstarch until smooth.

Temper the yolk mixture by slowly whisking in half a cup of the hot milk. Pour the egg mixture back into the saucepan with the remaining milk.

Cook over medium heat, whisking constantly, until it bubbles and thickens. Cook for exactly 1 more minute. Remove from heat, whisk in vegan butter and salt. Strain, cover with plastic wrap touching the surface, and chill for 3 hours.

Make Choux: Preheat oven to 400°F (200°C). Boil water, vegan butter, sugar, and salt in a saucepan. Remove from heat, add GF flour all at once, and stir vigorously.

Return pan to medium-low heat and cook for 2-3 minutes, mashing dough against the pan until a film forms on the bottom. Cool for 5 minutes in a mixer bowl.

Using a paddle attachment on medium-low, beat in the eggs in four additions, waiting until fully incorporated each time, until dough is glossy and falls in a 'V' shape.

Pipe 4-inch lines onto a parchment-lined baking sheet using a large star tip. Bake at 400°F for 15 minutes, then WITHOUT OPENING OVEN, reduce to 350°F (175°C) and bake 20-25 more minutes.

Turn off oven, poke a hole in each eclair to release steam, and let sit in the propped-open oven for 15 minutes. Cool completely on a wire rack.

Melt chocolate chips and coconut milk in the microwave until smooth to create the glaze.

Slice eclairs horizontally. Pipe the chilled pastry cream onto the bottom halves. Dip the top halves in the chocolate glaze, place on top of the cream, and garnish immediately with crushed nuts.