2 sticks (8 ounces) unsalted butter
8 ounces semisweet chocolate chips, or bars, cut into bite-size chunks
5 large eggs
1/2 cup sugar
4 teaspoons flour
8 extra-large paper muffin cups (separated, if foil-lined; foil reserved or discarded)
1 container (6 ounces) raspberries flicked with water and rolled in sugar before
Adjust oven rack to middle position; heat oven to 450 degrees. Line a muffin tin (1/2 cup capacity) with muffin papers (they should extend above cups to facilitate removal.); coat papers with vegetable cooking spray.
Melt butter and chocolate in a medium heatproof bowl over a pan of simmering water; remove from heat. With a hand mixer, beat eggs, sugar, and salt in medium bowl until sugar dissolves. Beat eggs, then flour, into chocolate until smooth.
Divide batter among prepared papers. Bake until batter puffs, but center is not set, 8 to 10 minutes. Remove and let stand 5 minutes. Carefully lift cakes from tin and transfer to a dessert plates; remove papers (or not). Flick raspberries with water and roll in remaining sugar. Top each with sugared berries and serve.