Cook pasta in boiling water until al dente, about 10 minutes or as package label directs. While pasta is cooking, warm remaining 1 Tbsp. oil in a large skillet over medium-high heat. Add garlic and sauté until fragrant, about 30 seconds. Add kale and cook, stirring, until wilted, 1 to 2 minutes. Reduce heat to medium-low and add cream, lemon zest and juice, 1/4 tsp. salt and red pepper, if desired. Cook, stirring, until mixture is just bubbling, about 2 minutes.