Preheat the oven to 425℉ convection bake.
Wash the tomatoes well, remove stem ends and cut into large chunks. Remove any bad spots and discard. Cherry tomatoes can be left whole. Cut the onion into large chunks and leave the garlic cloves whole with the skins on. Cut the sweet potatoes in half lengthwise.
Add the tomatoes, onion, and garlic to one large sheet pan and the sweet potatoes, cut side down, to another. Drizzle everything with the olive oil, salt, pepper, and sugar and toss well with your hands to coat. Make sure to coat the entire sweet potatoes, then return them cut side down to the pan.
Roast both pans for about 25 minutes until the tomatoes are beginning to brown slightly and the sweet potatoes are soft.
Cool slightly and use your hands or tongs to remove the peel from the sweet potatoes. If the cut sides are a bit charred, that's ok, or you can easily peel it off if it's too black. Remove the garlic from the skin.
Blend the soup in 2 or more batches, adding an even amount of sweet potato, tomato, onion, garlic, and cream to each. Include the pan juices. Pour into a soup pot while you blend the next batch. At this point you can taste and add seasoning. Adjust the consistency of the soup by adding a bit of water, broth or cream if it's too thick and simmering on the stovetop if it's too thin.
Garnish each bowl with a drizzle of honey and cream (what's left in the measuring cup is probably perfect), a pinch of flakey salt, fresh cracked pepper, crushed red pepper flakes, Parmesan cheese and fresh basil leaves. Serve with crusty bread or grilled cheese sandwiches for dunking.