Preheat oven to 400 degrees F.
In a food processor, combine flour, 1/4 cup sugar, and baking powder. Pulse once or twice. Add butter by tablespoons and process until butter is incorporated and mixture is reduced to small crumbs (it will not form a ball).
Pour crumb mixture into a 9-inch tart pan with removable bottom. Press crumbs gently over the bottom and half-way up sides of pan, approximately 1/8-inch thick. Do not pack mixture down too firmly. Bake for 10 minutes.
While crust is baking, combine egg yolks, sour cream, remaining 1/4 cup sugar, vanilla extract, and lemon zest.
Remove baked crust from oven and immediately pour egg yolk mixture into the hot crust. Return to oven for approximately 10 minutes or until the internal temperature registers at least 160 degrees F. on your cooking thermometer.
Remove from oven, let cool, and then refrigerator until serving time.
When ready to serve, arrange whole strawberries on top of the custard. Lightly brush the strawberries with the Fruit Glaze.
To serve, lift the tart from the side of the pan and place on a serving dish or cake plate.
Fruit Glaze Recipe:
2 tablespoons apricot jam or red currant jelly (or use jam or jelly of your choice)
2 tablespoons water
In a small saucepan over medium heat, stir together the jelly and water until syrupy. Remove from heat and let cool.