1 package (10 ounces) frozen strawberries in syrup, thawed
1 tablespoon corn starch
Combine 2 cups flour, sugar, undissolved yeast, corn starch, lemon peel and salt in a large bowl. Heat milk, water and butter until very warm (120° to 130°F); gradually add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add eggs and 1 cup flour; beat 2 minutes at high speed. Stir in remaining flour to make a stiff batter. Cover tightly with plastic wrap; refrigerate 2 to 24 hours.
Remove dough from refrigerator; roll on a lightly floured surface to 1/4-inch thickness. With a 3-inch cookie cutter, cut 24 circles; place on ungreased baking sheets. From remaining dough, using a 3-inch doughnut cutter, cut 24 circles and place on top of rounds. Cover; let rise in warm, draft-free place until almost doubled in size, about 45 minutes.
Prepare Strawberry Filling (see recipe below); set aside.
Preheat oven to 375°F and bake tarts for 10 minutes. Spoon Strawberry Filling into center of tarts. Return to oven; bake an additional 5 minutes or until evenly light golden brown. Remove from baking sheets; cool on wire rack. Sprinkle generously with sifted powdered sugar.
Strawberry Filling: Combine strawberries and corn starch in a saucepan. Cook over medium heat, stirring constantly until mixture comes to a boil, about 2 to 3 minutes. Remove from heat; let cool.