01 - 
                Set the oven to 350F. Lightly spray and line a 9x9 baking pan with parchment paper, if desired, to enable you to lift out the blondies for neater cutting.
              
              
              
                02 - 
                Beat the butter and sugar together for several minutes until smooth and fluffy. Beat in the egg and vanilla.
              
              
              
                03 - 
                Mix in the mashed banana, and then the flour and salt. Mix just until everything is well blended, don't over mix.
              
              
              
                04 - 
                Spread into your prepared pan. Bake for 25 to 30 minutes, until the center is set. I check with a toothpick.
              
              
              
                05 - 
                Let the cake cool most of the way before you make the frosting.
              
              
              
                06 - 
                To make the caramel frosting put the butter, brown sugar and milk or cream in a small saucepan and melt the butter, whisking all the time. Continue whisking until the mixture comes to a boil, then turn off the heat and add the sifted powdered sugar, whisking until completely smooth. You may need to add a little bit more powdered sugar if it seems very thin.
              
              
              
                07 - 
                Spread it immediately onto the cake, it will set up very quickly. Enjoy!