Why This Recipe Works
Raspberry squares are one of the best, and easiest, bar cookies to prepare, especially since the filling is ready-made (a jar of raspberry preserves). But sometimes the proportions are uneven, leaving one parched from too much sandy crust, or with a puckered face from an overload of tart filling. We were after a buttery, tender, golden brown crust and crumb topping with just the right amount of sweet and tart raspberry preserves in the middle. For the tender, almost (but not quite) sandy crumb, we had to get the right combination of ingredients, especially the butter and sugar. Too much butter made the raspberry squares greasy, but too little left them on the dry side. We found that equal amounts of white and light brown sugar made for a deeper flavor than white alone; oats and nuts made a subtle contribution to flavor while also adding some textural interest. For a golden brown bottom crust, we prebaked it before layering it with raspberry preserves and sprinkling on the top crust, which was a small amount of the reserved bottom crust mixture.