In a small bowl, stir together 1/2 cup bread flour, 1 tablespoon sugar, and 2 1/4 teaspoons instant yeast to make the sponge.

Add 1/2 cup water and stir until a smooth batter forms.

Cover the bowl with plastic wrap and ferment at room temperature for 60-90 minutes, until foamy.

In a 4-quart mixing bowl, combine 6 tablespoons sugar, 1 teaspoon salt, 1/4 cup powdered milk, 2 tablespoons butter, and 2 tablespoons shortening.

Cream together until smooth, then mix in 2 eggs and 1 teaspoon lemon extract, 1 teaspoon orange extract and 1 teaspoon vanilla extract.

Knead in the sponge and 3 cups bread flour.

Add water, as needed, to form a soft dough.

Knead for 10-12 minutes with an electric mixer or 15 minutes by hand until supple and soft.

Perform a windowpane test to ensure gluten development.

Lightly oil a large bowl and transfer the dough, coating with oil.

Cover with plastic wrap.

Ferment at room temperature for approximately 2 hours, or until the dough doubles in size.

Remove the dough and divide it into 2 equal pieces.

Form each piece into a boule.

Lightly oil two 9-inch pie pans and place 1 boule, seam side down, in each pan.

Mist the dough with spray oil and cover loosely with plastic wrap.

Proof at room temperature for 2-3 hours, until the dough fills the pans and doubles.

Gently brush the loaves with egg wash (1 egg whisked with 1 teaspoon water).

Preheat oven to 350F.

Bake for 50-60 minutes, or until they register 190F in the center.

Rotate loaves after 30 minutes for even baking.

Remove bread from pans and cool on a rack.

Allow to cool for at least 90 minutes before slicing or serving.