In a small bowl, combine warm water and sugar, stirring gently. Allow this mixture to sit for about 5 minutes until it becomes foamy on top.

In a stand mixer, mix together both bread flour and all-purpose flour with salt until well combined. Slowly pour in the activated yeast mixture while mixing on low speed, forming a sticky dough.

Transfer the sticky dough to a lightly oiled bowl, cover, and let it rise in a warm spot for about 1 hour until doubled in size.

Gently deflate the dough and transfer it to a greased 9x13 inch pan. Stretch and fold the dough, brush with olive oil, cover, and let it rise for another hour.

Preheat your oven to 425°F (220°C) while the dough rises.

Create dimples in the dough, spread raspberry jam evenly, covering all the dimples.

Bake for about 18-22 minutes or until golden brown and cooked through.

Poke holes in the baked focaccia and fill with additional raspberry jam.

Mix powdered sugar and milk for the glaze, drizzle over the focaccia, and flip to ice the other side.

Slice into squares and serve warm.