Salt-packed capers are ideal for these Italian crêpes because they keep their flavor better than the ones stored in vinegar. Capers from Pantelleria in the Lipari Islands are particularly delicious.
In a food processor, pulse the corn kernels to a coarse puree. In a medium bowl, beat the eggs to mix. Stir in the corn puree, flour and salt, then whisk in the milk. Stir in the 2 tablespoons of melted butter, cover with plastic wrap and refrigerate the corn batter for at least 1 hour or overnight.
Preheat the oven to 300°. Let the batter return to room temperature, then whisk it gently. Heat an 8-inch crêpe pan or nonstick skillet. Dip a paper towel into about 2 tablespoons of melted butter and rub the bottom and side of the crêpe pan generously with the butter. Set the pan over moderately high heat. Pour in 3 tablespoons of the batter and tilt the pan to distribute it evenly; pour any excess batter back into the bowl. Cook the crespella until browned on the bottom, about 1 minute. Turn the crespella and cook the second side for about 10 seconds, then slide it out onto a baking sheet. Repeat with the remaining batter to make 12 crespelle, overlapping them slightly on the baking sheet. Just before serving, cover the crespelle loosely with foil and rewarm them in the oven for about 3 minutes.
Spread the paler side of each crespella with 2 tablespoons of mascarpone. Top with 1 tablespoon of scallions and roll up or fold into quarters. Set 2 crespelle on each plate, sprinkle with 1 teaspoon of the capers and some of the remaining scallions and serve at once.
Wine Recommendation: The delicate flavors and buttery-creamy texture of the mascarpone and the sweetness of the corn-based crespelle call for a round and rich-flavored sparkling wine with a mouth-filling texture. The wine also needs enough acidity to stand up to the pungent capers. The superlative Nonvintage Bellavista Franciacorta Brut fills the bill admirably.
Notes: Salt-packed capers are available at specialty food shops and Italian markets. Brined capers that have been rinsed can be substituted.