In the bowl of a stand mixer, combine the warm water (105-115°F) and sugar. Quickly whisk by hand until the sugar dissolves completely. Add the active dry yeast and whisk again until combined. Allow the yeast mixture to sit for 5 minutes. If the yeast doesn’t begin to bubble, your yeast might be expired; it’s best to start over with fresh yeast, as this is crucial for a good focaccia.

Attach a dough hook to your stand mixer. Add the bread flour, all-purpose flour, and salt to the yeast mixture in the mixing bowl. Mix on medium speed until a sticky dough forms, making sure the ingredients are well incorporated but not over-mixed.

In a large mixing bowl, coat the sides with 2 tablespoons of olive oil. Transfer the sticky dough from the mixer to the oiled bowl, then use your hands to spread a bit more oil on the surface of the dough. Cover the bowl with plastic wrap and place it in a sunny window or another warm spot for about an hour to let it rise. The warmth really helps the dough double in size—I always look for a cozy spot in my kitchen for this.

Once the dough has doubled, use a silicone brush to grease a 9×13 metal baking pan with 2 tablespoons of olive oil. Gently move the dough into the prepared pan. Fold it in thirds over itself a couple of times, flipping as needed to ensure the dough gets coated in oil and is kneaded slightly for even gluten development. Cover again with plastic wrap and let rise in the same warm spot for another hour, until the dough has doubled again and spreads to the edges of the pan.

When the dough is fully risen in the pan, preheat your oven to 425°F. Pour the remaining 2 tablespoons of olive oil over the dough. Use your fingers to poke deep holes all over the surface; you want to see the bread forming pockets and bubbles. Use a spoon to gently spread about ¼ cup of raspberry preserves over the unbaked dough, making sure some collects in the grooves you just made.

Bake the focaccia in the preheated oven for 18-22 minutes, or until the surface is golden brown and the bread is cooked through. Once removed from the oven, use a large straw to poke multiple deep holes (about 35) into the bread—these will hold the filling. Immediately, while the bread is still warm, use a small spoon to fill each hole with more raspberry preserves. The residual heat helps the jam melt into the bread. I like to be generous here—the more filling in each bite, the better!

Once the bread is slightly cooled, prepare the icing: Using an electric hand mixer, combine the confectioners’ sugar with whole milk, adding milk one tablespoon at a time, until the icing is thin enough to spread but thick enough that it will harden when set. Spread the icing over the top of the focaccia. If you have extra time or want a truly glazed experience, once the top sets, carefully flip the bread onto a wire rack and glaze the bottom as well—just like a real donut! Cut the finished bread into squares and serve.