Make breadcrumbs; heat butter and toast breadcrumbs with some zest: In a food processor, pulse bread into very coarse breadcrumbs (you should have 1 cup). Melt 2 tablespoons butter in a small skillet over medium-high heat. Add breadcrumbs and 1 teaspoon grated zest. Cook, stirring, until crumbs are golden and crisp, about 3 minutes. Remove from pan; let cool completely.

Combine eggs, yolks, cream, cheese, and zest: In a large bowl, whisk together eggs, yolks, cream, cheese, and remaining 1 1/2 teaspoons grated zest.

Cook pasta: Bring a large pot of salted water to a boil. Add pasta and cook until al dente, about 2 minutes less than package directions. Drain, reserving 1 cup pasta water.

Add pasta to cheese mixture; add remaining butter and lemon juice: Add pasta to bowl with cheese mixture. Season with a generous amount of pepper and some salt. Use tongs to toss until pasta is fully coated. Add remaining 4 tablespoons butter and lemon juice; toss until a creamy sauce forms. (If necessary, thin with a little pasta water, 1 tablespoon at a time.),

Serve: Serve pasta sprinkled with breadcrumbs, pistachios, more cheese, chives, and julienned lemon zest.