Preheat oven to 350 °F. In a medium bowl, combine almond meal, brown sugar, and salt. Whisk together and then stir in melted butter. Stir until combined.
Line an 8×8 baking dish with foil for easy removal and press the almond meal crust into the foiled pan, working it up the edges a bit. Bake the crust at 350 degrees for 20 minutes.
For the lemon filling, zest and juice 2-3 lemons and whisk together all ingredients until well combined. Make sure the cornstarch isn’t clumped together.
When crust is done baking, pour in lemon filling and return to the oven. Bake for 15 minutes.
While lemon bars are baking, chop thawed cherries finely. Add to a small pot with juice from cherries and sugar. Bring to a simmer, turn heat down to low, and simmer for 5 minutes to thicken. Mash cherry mixture as it simmers with a fork. Then add cornstarch + water mixture and cook for another 2-3 minutes. Remove from heat and let cool.
When lemon bars come out of the oven, scoop over cherry swirl topping and use a knife to gently swirl it into the bars.
Let lemon bars cool to room temperature. Then cover them with plastic wrap and chill in the fridge for at least a few hours (or overnight).
When ready to serve, remove bars from the pan by lifting out the foil. Peel foil down from the sides of the bars and chop them into 12 even pieces. Dust bars with powdered sugar and extra lemon zest.
Store extra bars in the fridge in an airtight container for 4-5 days.