In a small bowl, combine warm water (105-115°F) and sugar, whisking until fully dissolved. Add active dry yeast and let sit for 5 minutes.

In a large mixing bowl, combine bread flour, all-purpose flour, and salt. Gradually pour in the activated yeast mixture, mixing until a sticky dough forms.

Lightly oil a large bowl, place dough inside, cover, and let it rise in a warm place for about 1 hour until doubled in size.

Pour olive oil into a 9x13 pan, swirl to coat. Transfer dough into pan, folding it lightly. Let rise for another hour.

Preheat oven to 425°F with 15 minutes left of the second rise.

Poke holes in the risen dough and spread raspberry jam into the holes.

Bake in preheated oven for 18-22 minutes until golden brown.

Remove from oven, poke additional holes and fill them with more raspberry jam.

Mix powdered sugar and milk until desired icing consistency. Drizzle icing over the cooled focaccia.

Slice into squares and serve warm.