In a large mixing bowl, combine the warm water, instant yeast, and honey. Stir gently and let it sit for about 5-10 minutes until it becomes frothy.
Once the yeast mixture is frothy, add in 3 1/2 cups of all-purpose flour and kosher salt. Mix until a shaggy dough forms.
Transfer the dough to a floured surface and knead for about 5-7 minutes, until it is smooth and elastic. Place the dough in a greased bowl, cover it, and let it rise for about 1 hour.
While your dough is rising, combine the mascarpone cheese, shredded fontina cheese, grated parmesan cheese, minced garlic, fresh thyme, crushed red pepper flakes, chopped spinach, and marinated artichoke hearts in a medium bowl.
Once the dough has risen, punch it down and roll it out into a large rectangle, about 1/4 inch thick.
Spread the cheesy filling evenly over the dough rectangle. Cut the dough into strips about 2 inches wide and stack the strips.
Carefully cut the stacked strips into squares and arrange them upright in a greased loaf pan.
Cover the loaf pan and let it rise for another 30 minutes. Preheat your oven to 350°F (175°C).
Brush the top of the loaf with melted butter and sprinkle with coarse pretzel salt.
Bake the bread for about 25-30 minutes, until golden brown and cooked through.
Allow the bread to cool in the pan for about 10 minutes before transferring it to a wire rack. Serve warm.
