Preheat your oven to 350°F (175°C). Line a 9×13-inch baking pan with parchment paper, letting it hang over the long sides to create handles. Lightly grease the parchment to make it easy to lift the bars out after baking.
In a large mixing bowl or stand mixer, beat the softened butter and granulated sugar together on medium speed until light and fluffy, about 2–3 minutes. The mixture should look pale and airy.
1 cup unsalted butter, 1 3/4 cups granulated sugar
Add the eggs one at a time, mixing well after each addition and scraping down the bowl as needed. Mix in the vanilla extract and almond extract. The batter will be smooth and thick, similar to cake batter.
4 large eggs, 2 teaspoons vanilla extract, 1/2 teaspoon almond extract
In a separate bowl, whisk together the flour, baking powder, and salt. Add the dry mixture to the butter mixture in 2–3 additions, mixing on low speed just until no dry streaks remain to avoid overmixing.
3 cups all-purpose flour, 1 teaspoon baking powder, 1/2 teaspoon fine sea salt
Scoop out about 1 1/2 cups of the dough and set it aside in a small bowl. This portion will be used to dot over the cherry filling as a topping.
Spread the remaining dough into the prepared pan. Use a spatula or your fingers (lightly floured or sprayed with nonstick spray) to press it into an even layer, pushing slightly up the edges to help hold in the filling.
Spread the cherry pie filling evenly over the crust, reaching all the corners so every bar has fruit. If using canned filling, stir it briefly in a bowl first so it spreads evenly.
42 oz cherry pie filling
Tear the reserved dough into small pieces (about nickel- to quarter-sized) and scatter them over the cherry filling. You do not need to cover the surface completely; some exposed cherry will bubble up attractively.
Bake for 35–40 minutes, or until the top is lightly golden and the edges are set. The center should be just barely jiggly but not wet. Start checking around 32 minutes, as oven temperatures can vary.
Let the bars cool in the pan on a wire rack for at least 1–2 hours. For the cleanest slices, cool to room temperature, then chill for 30–60 minutes so the filling can fully set.
For the glaze, whisk together the powdered sugar, 2–3 tablespoons of milk or heavy cream, and vanilla or almond extract until smooth and pourable.
1 cup powdered sugar, 2-3 tablespoons milk or heavy cream, 1/2 teaspoon vanilla or almond extract
Drizzle the glaze over the cooled bars. Use the parchment handles to lift the slab from the pan onto a cutting board, then cut into 24 squares (or 18 larger bars), wiping the knife between cuts for neat edges.