If neighborhoods could compete with one another over carbo-loading dominance, Rittenhouse Square would be sitting fat and pretty atop those power rankings.

It's a bakery- and dessert-heavy area, with LeBus, Miel, Max Brenner, Swiss Haus, plus the original Metropolitan location and its cafe, competing for sugar-dusted biz.

But there's still some room for newcomers to flex — hence the two-day-old Bakeshop on Twentieth (269 S. 20th St., 215-644-9714), Mark and Lisa Cosgrove's sweet addition to an already-busy block.

Both Cosgroves have considerable food-world experience. Mark, a Restaurant School grad who also schooled under Steve Poses at the influential Frog Commissary, was formerly involved with Spread Bagelry, across 20th Street from his new place. (Though this project was initially associated with Spread, that is no longer the case.) Lisa, more recently a network administrator in the corporate IT world, ran her own at-home wholesale baking business, selling breads and sweets to local farmers' markets.

At that time, low-fat and no-fat goodies were in high demand. Now? "No one says 'fat-free' anymore," says Lisa. "Fat is not the problem." She'll soon introduce gluten-free and sugar-free options to the fray, but at the moment, her baked-on-premises lineup is focused on flavor and variety.

Signature display-case items include maple pecan blondies; sticky buns; jam-filled corn muffins; a number of scones; and the "Rittenhouse Square," a next-level fudge brownie featuring a pretzel crust and caramel topping. Right now they're also doing traditional and raisin challah loaves and apple honey cake for customers celebrating the High Holy Days. Coffee is by La Colombe, with an expanded drink menu on the way.

The Bakeshop, open seven days a week from 7 a.m. till when sells out (usually around 5 p.m.), will add savory items, like soups, sandwiches and hand pies, to the menu in the coming weeks.

Hours will expand into the evening to accommodate a to-go dinner crowd. Also joining the roster in the near future: local baker and cake decorator Meg Skill, who peddles her wares under the name Nutmeg Treats. She'll execute all of the shop's custom cake orders.