For crepe batter, in a small bowl, beat the eggs, milk and butter.

Combine flour and salt; add to egg mixture and mix well.

Cover and refrigerate for 1 hour.

In a small skillet, cook sausage and onion over medium heat until meat is no longer pink; drain.

In a large bowl, whisk the eggs, milk and mayonnaise. Stir in sausage mixture and cheese; set aside.

Heat a lightly greased 8-in. nonstick skillet. Stir crepe batter; pour 2 tablespoons into center of skillet. Lift and tilt pan to coat bottom evenly.

Cook until top appears dry; turn and cook 15-20 seconds longer.

Remove to a wire rack. Repeat with remaining batter, greasing skillet as needed.

Stack crepes with waxed paper or paper towels in between until cooled.

Line greased muffin cups with crepes; fill two-thirds full with sausage mixture.

Bake at 350°F for 15 minutes.

Cover loosely with foil and bake 10-15 minutes longer or until a knife inserted near the center comes out clean.