In a large mixing bowl, whisk together the strawberry lemonade, lemon zest, active sourdough starter, and salt until the starter dissolves.

Gradually add the bread flour, stirring until it forms a shaggy dough that pulls away from the sides.

Cover the bowl with a damp cloth and let it rest for 30 minutes.

Perform stretch and folds every 30 minutes for 1.5 hours, gently incorporating strawberries on the first stretch.

Allow dough to ferment in the bowl until risen by 50% and bubbly, about 5 hours.

Prepare a greased 9x13-inch baking pan with melted butter and transfer the dough.

Spread melted butter over the dough, and dollop and spread strawberry jam evenly over it.

Cover and let the dough rise until puffy for 1 to 2 hours.

Dimple the dough with fingers and pour remaining melted butter over top.

Preheat oven to 425°F (220°C) and bake for 27 to 30 minutes until golden brown.

Mix powdered sugar with a splash of strawberry lemonade for the glaze, drizzle over cooled focaccia.