Delights Cafe just started serving breakfast the week we arrived for our stay at The Signature. They offer a selection of baked goods, sandwiches, salads, and gelato/ice cream, along with drinks and other snack items. We were highly impressed with the quality of their food. During our stay we ordered lox on flatbread, brioche french toast ham-and-swiss panini, and the forest mushroom quiche -- all delicious and all prepared fresh. We also had yogurt and fruit parfaits every morning. Since you do have to wait while they prepare your meals, you can just relax outside on the patio that faces toward The Signature's private pool area on a nice day or inside the pleasant cafe itself.
You'll find Delights Cafe in Tower 2. It's a good value for the non-dinnertime Vegas-splurge, and very convenient while staying at The Signature.