Set the oven temperature to 350°F (177°C). Place a sheet of parchment paper in a 9-inch square baking pan, ensuring that it extends beyond the edges of the pan. This will allow you to easily remove the bars from the pan. Put aside.
Prepare the crust: In a medium bowl, combine the flour, 1 cup (85g) oats, brown sugar, baking powder, lemon zest, and salt. Mix them together using a whisk. Incorporate the liquefied butter and vanilla into the mixture, stirring until it takes on the texture of damp, crumbly sand without any areas that are still dry. The amount of crust mixture you will have is little over 3 cups, which is around 520 grams. Press two-thirds of the mixture, about two cups or 345 grams (precise measurement not required), onto the baking pan that has been prepared. Apply pressure to the mixture in the pan using your hands, a big spoon or spatula, or the bottom of a measuring cup in order to shape it into a crust. Place in the oven and bake for a duration of 10 minutes. Afterward, take it out of the oven and allow it to cool somewhat.
Prepare the filling: Position the cornstarch in a little container and place it nearby, easily accessible from the burner. Combine the cherries, sugar, and lemon juice in a medium saucepan over medium heat. Continuously whisk the mixture until the cherries start to release their juices, which typically takes about 4 to 6 minutes. As the cherries are cooking, carefully extract a few spoonfuls of the juice from the pot and incorporate it into the cornstarch dish. Combine the cornstarch and cherry juice using a fork until the cornstarch is fully dissolved. Incorporate this mixture into the filling, then heat until it reaches boiling point and continue to simmer, sometimes stirring, until the filling has become a thicker consistency, about 10 minutes. Take the mixture off the heat and include the almond extract by stirring it in.
Distribute the contents evenly onto the heated crust. Incorporate 2 tablespoons of oats into the remaining crumble mixture, then evenly distribute it over the filling, gently compressing it with the back of a big spoon or flat spatula.
Place in the oven and bake for about 40 to 50 minutes, or until the surface is gently browned and a toothpick comes out largely clean, with a few cherry particles. My task typically takes around 45 minutes to complete.
Take out of the oven and let the bars cool entirely in the pan placed on a wire rack. After about one hour, you may transfer the whole pan to the refrigerator in order to expedite the process.
Prepare the frosting, if desired: Combine the icing ingredients by whisking them together. If you want to have a thinner consistency, you may add more milk. Pour a little amount of liquid, such as a sauce or glaze, evenly over the bars when they have cooled.
Remove the bars from the pan by using the edges of the parchment paper liner and transfer them onto a cutting board. Use a sharp knife to cut the squares into slices, ensuring that you clean the knife between each cut for a tidy result.
To preserve any remaining cherry pie bars, whether they have icing or not, just cover them and keep them at room temperature for a maximum of 2 days. Alternatively, you may store them in the refrigerated for up to 1 week.
Written observations or records of information.
Instructions for preparing in advance and freezing: To preserve the cooled bars, you may place them in the refrigerator before slicing them into squares, as indicated in step 6. The baked and cooled bars may be frozen for up to 3 months. Allow it defrost overnight in the refrigerator and let it to room temperature, if preferred, before to serving.
Tools specifically designed for a certain purpose (affiliate links): The items needed for this recipe are a 9-inch square baking pan, a glass mixing bowl, a whisk, a citrus zester, a citrus juicer, and a cooling rack.
Is it permissible to use preserved cherries that are stored in cans or jars? I advise against using canned cherries in this dish. Canned cherries often include additional additives. If you are able to get a can or jar containing just cherries in liquid, these cherries are already extremely tender and will easily break down when cooked. I strongly advise against them in this context.
Is it OK to substitute sour cherries with dark sweet cherries? Indeed, we have conducted a thorough examination of this and can confirm that it works very well with two modifications: Decrease the amount of sugar in the filling to 1/3 cup (67g) and include an additional 1 teaspoon of lemon juice. However, if I had to make a decision, I would choose for sour cherries in this particular situation.
Is it possible to bake this in a 9×13-inch pan? Yes, it is possible to bake a larger quantity, however I have found that following the original recipe and using a 9-inch square pan yields superior results. To increase the quantity, double the amount of each ingredient by two and bake the mixture in a pan measuring 9×13 inches. Extend the duration of pre-baking the crust to 18 minutes. Extend the duration of baking after incorporating the filling and crumble topping to 1 hour, or until the filling starts to bubble.