Combine cherries, 2 tablespoons sugar, lemon juice, cornstarch, and almond extract in a saucepan over low heat. Cook, stirring occasionally and crushing cherries with a spoon, for 5 to 10 minutes. Remove from the heat and pour into a slow cooker.

Whisk flour, baking powder, and cinnamon together in a bowl. Cream 3/4 cup sugar and butter together in a separate, large bowl until light and fluffy. Add eggs, one at a time, beating well after each addition. Beat in milk. Mix in flour mixture just until incorporated. Add to the slow cooker.