In large mixing bowl, combine sliced peaches, lemon zest and juice, sugar, and salt.
Transfer peaches and juices to colander placed in a large bowl to capture juices.
Once the mixture has stopped releasing juices, approx. 10 minutes, there should be up to 1 cup of juice.
Place juice in small saucepan.
Boil juice over medium-high heat until liquid is syrupy and lightly carmelized. About ⅓ of the original amount should remain.
Meanwhile, transfer peaches to mixing bowl, add cornstarch and almond extract, and stir until all traces of cornstarch have disappeared.
Pour syrup over peaches and combine gently. If any liquid hardens, it will dissolve during baking.