Prepare the yeast mixture by combining warm water and sugar, whisking until dissolved, then adding yeast. Let sit for 5 minutes until bubbly.

Mix the dough by adding bread flour, all-purpose flour, and salt to the yeast mixture. Mix on low speed until a sticky dough forms, about 3-4 minutes.

Let the dough rise in a bowl coated with olive oil, covered with plastic wrap, for about 1 hour until doubled in size.

Shape the dough by transferring it to a greased 9x13 pan, folding over itself, and letting it rise covered for another 1 hour.

Preheat the oven to 425°F while the dough rises for the second time.

After the second rise, poke holes in the dough, drizzle with olive oil, and swirl raspberry jam into the holes.

Bake for 18-22 minutes until golden brown; let cool slightly in the pan.

Prepare the icing by mixing powdered sugar and milk until desired consistency is reached.

Ice the focaccia and serve warm after poking additional holes and filling with more raspberry jam.