1Heat oven to 375°F. In medium bowl, mix flour, pecans and 1/4 cup sugar. Stir in 1/4 cup butter and 1 egg until crumbly. Press in bottom and up sides of 24 ungreased mini muffin cups. Bake 10 to 12 minutes or until light golden brown. Cool tart shells in pan.
2In 2-quart saucepan, sprinkle gelatin on cold water to soften. In medium bowl, beat 1/2 cup sugar and 2 eggs with electric mixer on high speed until thick and lemon colored; stir into gelatin mixture. Cook about 15 minutes or just until boiling over low heat, stirring constantly. Remove from heat. Stir in lemon peel, lemon juice and 2 tablespoons butter.
3Pour lemon mixture into tart shells. Refrigerate about 1 hour or until set. Store in refrigerator.