How to Make It
Bring 4 quarts water and 1/4 cup salt to a boil in a large pot over high.
Add Fresh Whole-Wheat Spaghetti to boiling water; cook, stirring occasionally, until just tender, 2 to 3 minutes. Lift pasta from water using a fine wire-mesh strainer, reserving pasta cooking liquid in pot. Drain pasta in strainer; set aside.
While pasta cooks, melt 1 tablespoon butter in a large skillet over medium. Add shallot and 1 tablespoon jalapeño slices; cook, stirring often, until softened, 1 to 2 minutes. Add crabmeat and wine; cook, stirring constantly, until reduced, about 10 seconds.
Add cooked pasta and 1/2 cup reserved cooking liquid to crabmeat mixture; let mixture come to a boil over medium. Add remaining 3 tablespoons butter; cook, tossing mixture constantly, until sauce thickens and coats pasta, 1 to 2 minutes, adding an additional 1/4 cup cooking liquid if needed to reach desired consistency. Stir in basil, scallions, remaining jalapeño slices, lemon zest and juice, and remaining 1/4 teaspoon salt. Toss to combine. Divide spaghetti evenly among 4 plates, and serve with lemon wedges.