In a small bowl, stir together the warm milk, yeast, and 1 teaspoon of sugar. Let stand for 5 to 10 minutes, until foamy.

In a large mixing bowl, combine the flour, 1/4 cup sugar, and salt. Add the yeast mixture, eggs, softened butter, vanilla, and lemon zest.

Mix until a soft dough forms, then knead by hand or with a dough hook for 6 to 8 minutes, until smooth and elastic. If needed, add a little more flour, one tablespoon at a time, if the dough is too sticky.

Place the dough in a lightly greased bowl, cover, and let rise in a warm place for 1 to 1 1/2 hours, or until doubled in size.

Grease a 9x13-inch baking pan or a similar rectangular pan. Punch down the dough and spread it evenly into the prepared pan. Let it rest, covered lightly, for 20 to 30 minutes.

Preheat the oven to 350°F (175°C). Arrange the sliced fruit evenly over the dough, pressing it in slightly.

Sprinkle the fruit with the remaining 2 tablespoons sugar, and add cinnamon and sliced almonds if using.

Bake for 30 to 35 minutes, or until the dough is golden brown and a toothpick inserted into the center comes out clean.

Cool slightly before slicing. Dust with powdered sugar if desired and serve warm or at room temperature.