Preheat oven to 350°F.: You will notice the kitchen beginning to warm, and that gentle thermal buildup is crucial so the phyllo shells crisp right away when they hit the heat. A properly preheated oven ensures even cooking, preventing underdone centers or overly browned edges. A common mistake is placing the tarts in before the oven reaches temperature, which can make the shells soggy instead of flaky. If your oven runs hot, place an oven thermometer inside to confirm true heat and rotate the tray halfway if you see uneven browning.
In a medium mixing bowl, combine all ingredients except pecans. Mix well. Stir in chopped pecans.: As you blend the butter , egg , brown sugar , honey , and vanilla , you will feel the mixture thicken and the sugar begin to dissolve, creating a glossy, slightly viscous mixture that clings to a spoon. This step ensures a uniform custard base so each tart bakes consistently. Folding in the chopped pecans at the end preserves their texture and prevents them from turning gummy. Overmixing can incorporate too much air, which leads to hollow pockets in the filling; stir until just combined and the sugar is mostly dissolved.
Arrange mini shells on a baking sheet. Fill mini shells with one heaping teaspoon of pecan mixture. If any of the mixture remains, distribute evenly between all the shells.: Lay the shells evenly spaced so hot air circulates and each shell crisps uniformly. As you spoon the filling, you should see the glossy filling settle and the pecans nestle into place. Avoid overfilling, which can cause spillover and uneven baking; a heaping teaspoon gives a rounded top that will caramelize without overflowing. If some tarts receive slightly more filling, gently redistribute with the back of the spoon while the mixture is still pliable. Watch for drips on the tray, wiping them away to prevent burning.
Bake for 10-15 minutes. Let them cool before serving.: During baking you will hear the faint crackle of the shells and smell the warm, nutty scent of honey and pecans toasting. Visually, the filling should set and take on a light golden hue at the edges, while the centers remain glossy but no longer jiggly. This texture signals the right doneness. Underbaking leaves a runny center, while overbaking can make the filling hard and the phyllo shells overly browned, so aim for that sweet spot. After removing from the oven, allow them to cool so the filling firms slightly, making them easier to lift from the shells without breaking. Plate them on a wire rack to prevent steam from softening the bottoms.