Preheat oven to 350 degrees F. Coat a 9-inch pie pan with cooking spray.

To prepare filling: Combine 1/2 cup sugar, honey and rhubarb in a large saucepan. Cook over medium-low heat, stirring often, until the rhubarb is juicy and softens slightly, about 5 minutes. Increase heat to medium; gradually add the cornstarch mixture. Cook, stirring constantly, until the juices thicken, 2 to 3 minutes.

Combine apricots, strawberries, orange zest and cinnamon in a large bowl. Mix in the rhubarb.

To prepare crust & bake tart: Mix oil and butter in a small bowl. Cover phyllo with wax paper or plastic wrap and a slightly damp kitchen towel to prevent it from drying out. Center one sheet of phyllo in the pie pan, letting the edges hang over; gently press it into the pan. Dampen a pastry brush with water and lightly brush some of the oil-butter mixture over the phyllo. Sprinkle 1/2 teaspoon breadcrumbs over the bottom. Repeat with 5 more sheets of phyllo, laying each at a 45 degrees angle to the previous one and sprinkling each with breadcrumbs.

Scrape the filling into the crust. Brush one of the remaining phyllo sheets with oil-butter mixture. Place another sheet on top at a 45 degrees angle. Repeat with the last sheet. Place the stack on the filling. Fold the overhanging phyllo up around the tart, creating a ruffled border. Dab any remaining oil-butter mixture on top. Sprinkle with the remaining 2 teaspoons sugar. Cut 4 slits in the center for venting.

Place the tart on a baking sheet and bake until nicely browned and bubbling slightly, 45 to 55 minutes. Cool on a wire rack to room temperature (about 1 1/2 hours). Dust with confectioners' sugar.