Heat oven to 350℉.
Spray a 9 inch x 13 inch pan with baking spray. Set aside.
Sift flour, baking powder, baking soda, and salt together. Set aside.
With an electric mixer, beat shortening and sugar until light and fluffy, about 3-4 minutes.
Add vanilla and eggs, one at a time, beating well after each addition.
Add flour mixture alternately with milk, beginning and ending with flour mixture.
Stir in strawberries.
Pour batter into prepared pan.
Bake until cake tests done, about 35-40 minutes.
Let cool in pan 15-20 minutes, then turn out and finish cooling.