Focaccia Barese

Ingredients

• 1 ⅔ cups all purpose flour
• 4 tsp white sugar plus a pinch for the yeast
• 1 ¼ tsp kosher sea salt (flake salt like Jacobsen's!)
• 1 packet (¼ oz) active dry yeast
• ¾ cup very warm water (~104℉)
• 3 tbsp extra virgin olive oil (we used Lucero Arbequina)
• ½ cup (packed) boiled and mashed potato, either one small or ½ large russet
• ¼ cup extra virgin olive oil (more if you like)
• 3 Tbs chopped fresh rosemary (about one large sprig)
• ½ tsp sea salt flakes, or to taste