Bring a large pot of salted water to boil over medium-high heat. Add your penne and cook until al dente—usually around 9 to 10 minutes depending on your brand. I personally drain it when it still has just a tiny bit of firmness because it'll finish cooking from the residual heat.
While pasta cooks, halve your cherry tomatoes and place them in a large bowl. Mince the garlic really fine and add it to the tomatoes along with the olive oil, salt, pepper, lemon juice, and red pepper flakes. Let this sit for a minute so flavors start getting cozy together.
Tear your fresh basil by hand instead of chopping it (this keeps it from bruising). Add most of it to the tomato mixture, saving some for garnish. Tear your mozzarella into bite-sized pieces too—don't worry about them being perfect.
Drain the hot pasta and pour it directly into the tomato bowl. This is the magic moment where the heat from the pasta slightly softens the mozzarella without totally melting it. Toss everything together gently, don't go crazy with the mixing.
Let it sit for exactly one minute after tossing. Not gonna lie, I tried skipping this once and the flavors weren't as blended. That minute lets everything marry together before serving.
Divide among four bowls and top each with toasted pine nuts, remaining fresh basil, and a sprinkle of Parmesan. Taste one bite and adjust the salt and pepper if you need to—this is your summer caprese pasta family meal, so make it exactly how you like it.