Make the chocolate craquelin. Use a food processor to pulse together ½ cup butter with ⅓ cup brown sugar just until combined. Add ½ cup flour, a pinch of salt, ½ teaspoon vanilla, and 3 tablespoon cocoa powder, and pulse until combined. Shape the dough into a disc and place it between two sheets of parchment paper. Roll it out until ⅛-inch thick and chill in the fridge for 1 hour or in the freezer for 30 minutes. Cut out 8 circles about 2 inches in diameter and keep the craquelin in the fridge until ready to use.
Preheat oven to 425 degrees F. Line a baking sheet with parchment paper.
Make the cream puffs. Combine ¼ cup butter with ½ cup water and a pinch of salt in a heavy saucepan. Heat over high heat and bring to a rolling boil. Lower the heat to low and add ½ cup flour to the butter water mixture. Beat with a wooden spoon until the dough comes together. Remove from heat and add the eggs one at a time, fully incorporating each egg before adding the next.
Drop dough by heaping tablespoons onto the prepared baking sheet for a total of 8 cream puffs. Top the cream puffs with the chocolate craquelin and bake for 20 minutes. Lower the oven temperature to 350 degrees F and continue to bake for another 10 minutes or until golden brown. The shells should sound hollow when done. Cool the shells completely on a wire rack.
Meanwhile, prepare the filling. Increase the oven temperature back to 425 degrees F. Toss 1 lb strawberries with 2 tablespoon honey and a pinch of salt. Spread on a lined baking sheet and roast for 15 minutes or until softened and jammy. Let cool.
Make the vanilla custard. Heat 2 cups milk and the seeds of 1 vanilla pod in a heavy saucepan over medium heat until simmering.
Whisk together 2 yolks and 1 egg with ¼ cup cornstarch, and ½ cup sugar in a large bowl. Slowly pour the hot milk in the yolk mixture in a stream, whisking constantly. Transfer mixture to saucepan and heat over low heat, stirring constantly. Cook until thick, about 6-7 minutes. Remove from heat and add 2 tablespoon butter. Strain the custard through a fine-mesh sieve and cover with plastic wrap directly touching the surface. Let cool completely. Gently stir in the roasted strawberries.
Cut tops of the shells. Top the bottom halves with fresh sliced strawberries and fill each cream puff with the vanilla custard. Top with the top buns and serve.