Selection of Raspberry, Passion fruit, Apricot and OrangePreparing the fruit: wash, peel, and seed the fruit as necessary. Most fruits are then pureed. Some fruits are used as they are and others are mixed with syrup from canned fruit. Because of their relatively neutral taste, pear, peach or apricot syrups are the best; they can even be mixed together. Preparing the Mold and Jelling Agent: On a baking sheet or other surface that can stand high temperatures without cracking or warping, place a sheet of nonstick parchment paper and set the metal frame, flan ring, or metal rulers on it; or simply line a small brownie pan with parchment paper. Cooking the Fruit Jelly: In a large saucepan, place the fruit pulp or fruit pulp-syrup mixture and the sugar. Bring to a rapid boil over high heat, stirring constantly with a spatula. Once a full, rolling boil is reached, start the cooking time; this will be from 4 to 9 minutes, always at a rapid boil and stirring constantly, depending on fruit used. Add the butter halfway through the cooking time. When it is time, remove the saucepan from the heat and immediately add the liquid jelling agent; stir vigorously for a few seconds to be sure that is completely mixed into the jelly mixture. To Mold, Cut, and Serve the Fruit Jellies: As soon as the jelling agent has been stirred in, pour the boiling hot fruit jelly into the frame or brownie pan. Allow to set and cool completely, which will take at least 2-3 hours. When the jelly is completely cold, run the blade of a knife all around the edge to detach it from the frame or paper; then cut it into squares about 1 inch. Lift off the frame; then roll the squares one at a time in granulated sugar (preferably large grained). This step is not absolutely necessary; it does, however, keep the jellies from sticking to each other if piled on top of each other when served and makes them more attractive. To Store: The uncut jellies will keep for 2 months wrapped in the non-stick parchment paper it is molded on. Placed in a box, and kept in a cool cellar or the refrigerator. If kept in the refrigerator, the jelly picks up a little moisture but it keeps its shine better. Once cut and rolled in sugar, the jellies will keep for a week in a closed container in the refrigerator; it is preferable to place them in individual paper cases if they are to be stored in this way to keep them from sticking together; these homemade fruit jellies are softer than commercial ones.