Heat olive oil in large nonstick skillet over medium-high heat and cook chicken, stirring occasionally, until chicken is golden, about 4 minutes. Stir in tomatoes and cook, stirring occasionally, 2 minutes. Stir in water and Knorr® Homestyle Stock Chicken until stock is melted. Reduce heat to low and simmer, stirring occasionally, 5 minutes. Whisk in cream cheese until smooth and cook, stirring occasionally, until chicken is thoroughly cooked, about 2 minutes. Stir in spinach and cook just until spinach is wilted, about 2 minutes.
Combine chicken mixture with hot penne in large bowl. Turn into 2-qt (2 L) baking dish, then evenly top with bread crumbs. Bake 10 minutes or until crumbs are golden.