Cream the cheese, butter, and sugar together until light and fluffy. Add a pinch of salt and the butter flavoring, and beat the mixture well. Add the eggs, one at a time, beating thoroughly after each addition. Stir in the flour. Gradually add the sliced strawberries, gently folding them in after each addition. Spoon the batter into a buttered and floured cake pan (loaf pans or mini-loaf sizes for gift- giving), and bake the cake in a preheated 325 degrees oven for 1 1/2 hours, until the cake begins to shrink from the sides of the pan. Place the pans on cooling racks until cooled; turn cakes gently onto wire racks.