In a bowl, set over a pan of simmering water, melt the chocolate and the butter together, stirring occasionally until smooth. In another bowl, whisk the eggs and the sugar until its well incorporated, about 1 minute. Add the warm chocolate mixture to the egg mixture and mix until smooth. Then add the flour and mix until you no longer see specks of flour.
Spray 8 small ramekins with cooking spray and place into a sheet tray.
Fill the 8 greased cups with the batter (3/4 the way up the ramekin). If not ready to cook, refrigerate for as long as 3 hours.
Prepare the grill for indirect cooking over medium heat (around 400°F).
Place the muffin pan or sheet tray with Individual ramekins over the indirect section of the grill and bake, with the lid closed, until the cake tops barely jiggle when you shake the pan, about 9-10 minutes (or as long as 14 minutes if the batter has been refrigerated).
While cakes are cooking. Combine fresh or frozen raspberries in a pan with sugar, a little water, and a squeeze of lemon juice. Cook over low heat just until the raspberries break down and the sugar is dissolved. Blend into a sauce.
Strain well through a fine mesh strainer. Transfer to a container and chill before serving.
Once removed from the grill, run a knife around each cake then quickly flip out all the cakes to avoid cakes continuing to cook. Serve immediately with coulis drizzled on top or on the side.