SHRIMP: Trim the cleaned and deveined shrimp, removing tails and slicing each shrimp in half through the back. Add lemon zest to the shrimp and set aside for up to 20 minutes (otherwise, refrigerate the shrimp until you’re ready to cook them).
PASTA: Cook the linguine in boiling and heavily salted water until the pasta is al dente, about 6-8 minutes, depending on the type used. Remove a cup or so of the pasta cooking water, set aside and drain pasta in a colander.
SAUCE: Meanwhile, melt butter in a large nonstick skillet over medium heat (hot high). Add garlic and red pepper (the garlic should just barely get brown at this cooking temperature) and cook for about a minute. Add shrimp and cook until just done, about 3 minutes, stirring often. The shrimp will curl up. Add the wine and lemon juice and bring to a simmer; cook until the sauce is slightly reduced, about a minute.
If you have enough room in the pan, toss in the drained pasta, mascarpone cheese and about ½ cup of the cooking water. (If your pan isn’t large enough, pour everything into a large bowl and mix everything there.) Toss well, using tongs, adding more cooking water as needed, until the pasta and shrimp are coated and the sauce looks creamy. As you toss, there should be just a little bit of the thin pasta water/sauce in the bottom. Remove from heat and toss in remaining lemon zest and fresh basil. Season to taste – particularly pepper – and serve immediately with Parmigiano-Reggiano cheese on top if desired.