Baking

The cake layers can be wrapped well in plastic and refrigerated for up to 2 days; trim the tops just before assembling.

The cake layers can be wrapped well in plastic and refrigerated for up to 2 days; trim tops just before assembling. The frosting can be refrigerated in an airtight container for up to 3 days. Before using, bring to room temperature; beat with the paddle attachment on medium-low speed until smooth. The frosting can be refrigerated in an airtight container for up to 3 days. Before using, bring to room temperature; beat with the paddle attachment on medium-low speed until smooth.

This tart may also be made in an 8-inch springform pan. Fit the dough into the pan, and press it up the sides. Trim so it is 1 3/4 inches high.

The extra tablespoon of flour, sprinkled into the center of each pastry circle, helps thicken the rhubarb juices as the tartlets cook.

If you have enough tartlet pans, use a second one over each to line the dough during baking to keep the crust from shrinking down the sides. You can also line the tartlet shells with parchment paper and dried beans; the shells will take a few minutes longer to bake.

If you are using pasteurized egg whites, you do not need to heat them before beating with the sugar and cream of tartar or coarse salt.

To produce interesting curves in the caramel drops, stand the skewers upright in flower foam or a heavy container while setting. If the caramel hardens before all the pecans have been dipped, rewarm it over low heat. A foolproof way to clean caramel from the pan is to bring it to a boil with a bit of added water.

The tart shell can be made a day in advance; avoid filling it until 1 to 2 hours before you are ready to serve it in order to keep the shell as crisp and flaky as possible.