The key lime pie filling is very similar to an actual key lime pie filling, since it uses condensed milk, and I typically use condensed milk to make my key lime pie. To make the filling for this Key Lime Macaron, simply boil the condensed milk with a little bit of butter and key lime zest until it achieves a fudge consistency.
- Prep Time: 1 hour
- Cook Time: 40 minutes
- Servings: 26 macarons
- Calories: 130 kcal
- 3 egg whites 100 grams, 3.5 oz
- 1/2 cup white granulated sugar 100 grams, 3.5 oz
- 1 cup almond flour 96 grams, 3.4 oz
- 3/4 cup powdered sugar 90 grams, 3.17 oz
- Green food coloring
Key Lime Pie Filling
- 1-14 oz can of condensed milk
- 1 tablespoon unsalted butter
- 1-2 tablespoons key lime zest
- 2 egg whites
- 1/2 cup granulated sugar 100 grams, 3.5 oz.
- 1/4 teaspoon cream of tartar
- 1/8 teaspoon fine sea salt
- 1 teaspoon vanilla extract
- 1/4 cup white chocolate chips optional to drizzle on top
- 1/4 cup graham cracker crumbs
- Before you start, get all of your ingredients ready. Prepare a large piping bag, fitted with a large round tip.
- Line two baking sheets with parchment paper or silicon mat.
- I use a baking mat with the macaron template already in it. You can make your own or print it from the internet, and just place it under silicon mat, or parchment paper. I recommend using a silicon mat if you want more uniform bottoms.
- Measure out all of your ingredients.
- Sift powdered sugar and almond flour together. Set aside.
- Place egg whites and granulated sugar in a heat proof bowl or in a double boiler. Over a pan of simmering water, whisk the whites and sugar until frothy and sugar completely melted. It will take a couple minutes. You can test by touching the mixture between your fingers, and if you feel any sugar granules just keep whisking mixture over the water bath.
- Make sure the bottom of the bowl isn’t touching the simmering water.
- Transfer mixture to the bowl of a stand mixer.
- With the whisk attachment, start whisking mixture on low for about 30 seconds, then gradually start increasing speed to medium. Whisk on medium for one minute, until mixture is white and starting to become fluffy. Raise speed to high for 2-3 more minutes until stiff peaks are formed. Best way to check this is to keep your eye on the whites. Once they get glossy and you start seeing streaks formed by the whisk, it might be time to stop.
- You don’t want to overbeat the mixture at this point, because you don’t want to add too much air to it. Just whisk until stiff peaks have formed. You will notice the bird’s beak shape the peak will form and that will tell you the meringue can stop being whipped.
- Pour powdered sugar and almond flour into stiff whites.
- Start folding gently forming a letter J with a spatula. Add the food coloring at this point, if using.
- It’s time to stop folding when the batter is glossy and has a thick and flowing consistency. There are several ways to test this, and you might have to have a couple failed batches before you get this right.
- First, I pick up some batter with my spatula and try to draw a figure 8 with the batter that is dripping off the spatula. If you can form several 8 figures without the batter breaking up, that’s one indication that it might be ready.
- Then, I grab a teaspoon of batter and spoon onto my parchment paper or silicon mat.
- If the batter stays stiff and doesn’t spread out a bit, I start folding a little bit more, about 3 folds.
- Test again.
- Once the batter spreads out a bit and starts to look glossy on the parchment paper, I transfer my mixture to the piping bag.
- You don’t want your batter to be too runny either. So be careful not to overmix. It’s always best to undermix and test several times until the proper consistency has been achieved.
- This is the most important part about making macarons in my opinion.
- Once you’ve piped as many circles as you could, bang the trays against the counter a few times each. This will release air bubbles that are in the batter and prevent your macaron shells from cracking.
- Let your trays sit for a while so the shells will dry out a little bit. I usually leave about 20-40 minutes, depending on how humid the day is. You’ll know they’re ready when you gently touch the surface of a macaron and it seems dry.
- Pre-heat the oven to 325F.
- Bake one tray at a time.
- Bake for 4 minutes, rotate tray.
- Bake for 4 more minutes, check if it needs to be rotated again. You will know if it needs to be rotated again depending on how the macarons are baking. Take a look at them, if one side seems taller than the other, maybe you have to rotate the tray again.
- Bake for around 4 minutes or so. Really keep an eye out, not to overbake. I would say I bake for a total of 18-20 minutes.
- When baked, the macarons will have a deeper color and formed feet.
- Remove from the oven and bake the other tray.
- Let the macarons cool down before proceeding with the filling.
Key Lime Pie filling
- Place all ingredients in a small saucepan.
- Bring to a boil over medium heat.
- Keep stirring, non-stop, for 10-15 minutes while the mixture simmers. Don’t let the heat be too high, or it will burn the fudge. Also, don’t stop stirring, or that will also burn the fudge.
- The fudge will be ready when it’s very thick and you can see the bottom of the pan easily as you stir with your spatula.
- Tilt the pan over, and if the fudge comes off the bottom all at once, you can probably remove from the heat.
- Place it in a heat proof bowl, let it cool down all the way.
- Place room temperature filling in a piping bag.
- Mix all ingredients, except for the vanilla extract together in the bowl of a stand mixer.
- Set the bowl over a pot of simmering water over medium heat.
- Whisk mixture while it sits in the double boiler.
- Keep whisking over simmering water until it reaches 140F.
- That way the egg whites will be in a safe temperature to be consumed.
- Move bowl to the mixer.
- Whip with the whisk attachment for about 5 minutes on high speed.
- Add vanilla and mix to combine.
- Pipe the marshmallow frosting around the edges of the bottom shell macarons.
- Fill with the key lime pie filling.
- Place another shell on top.
- Drizzle white chocolate and graham crackers on top.
- Use a torch to toast the sides of the marshmallow.
- These macarons will store nicely in the fridge for up to 5 days. The marshmallow frosting doesn’t keep for too long, so I don’t recommend freezing them.