In a medium bowl, whisk together the eggs, sugar, and salt. Sift the flour into the bowl, and stir in along with the milk. Mix until smooth and well blended. The batter should be thin.
Heat a griddle or skillet over medium heat. Lightly oil the pan or spray with cooking spray. Pour about 2 tablespoons of the batter, or as much as desired, into the pan. Tilt the pan to spread the batter out evenly. When the edges are crisp looking and the center appears dry, slide a spatula carefully under the blin. Flip, and cook for about 1 minute on the other side, or until lightly browned.
Remove blini to a plate. Put a little butter on top, and continue to stack the blini on top of each other. To serve, spread with desired filling, then fold in half, and in half again to form a triangle. Mmm Mmm!