Key lime pie is one of my all time favorite desserts. When we visited the Florida keys, I think we ate key lime pie at four different places. 🙂 I’ve made different variations over the years, but wanted to try this one because it uses Nilla Wafers as the crust instead of the traditional graham crackers and we love Nilla wafers.
Do you need to use key limes for key lime pie? Thankfully the answer is no! Key limes are tiny and hard to juice and sometimes hard to find. The difference between key limes and Persian limes is that Persian limes have a higher acid content and are thus more tart. Key lime juice is a little more mild.
America’s test kitchen did a test way back where they made key lime pie with both types of juice and said they were pretty similar….just slightly more tart filling with the Persian limes. You can add the juice of a few clementines to your lime juice if you don’t have key limes but want the less tart juice. I personally love super tart key lime pie, so I just use Persian limes.
This is a pretty standard lime curd/custard filling. You can tell it is fully cooked when it only jiggles slightly and is 145-150 on an instant read thermometer. Ovens very widely, so it is better to judge doneness of custards by their temp as well as appearance, not time. If you overbake the filling, it will be grainy, not smooth and creamy.
Key Lime Pie Bars
Ingredients
For the crust:
- 2 cups Nilla Wafer crumbs 250g
- 5 tbsp melted butter unsalted
For the filling:
- 1 tbsp lime zest
- 5 large egg yolks
- 22 oz sweetened condensed milk 1 14 oz can plus 3/4 cup from a second can
- 1 cup freshly squeezed lime juice or replace 1/4 cup with clementine juice to mimic key limes
For the topping:
- 1 cup heavy cream
- 2 tbsp powdered sugar
- 1 tsp vanilla
Instructions
For the crust:
- Adjust oven rack to the middle and heat to 350. Line an 8×8 pan with parchment paper so it hangs over the sides to remove the bars when done.
- Grind the Nilla wafers until crumbs and mix with the butter. Transfer to the pan, and press the crumbs into the bottom/sides of the pan.
- Bake for 10-15 minutes until golden brown and fragrant. Cool completely.
For the filling:
- Whisk the egg yolks and zest by hand or in a mixer until fluffy and light in color.
- Add the sweetened condensed milk and beat for another 2-3 minutes.
- Whisk in the lime juice. Pour into the crust and place into the oven for 15-20 minutes until the filling is set but still has a little jiggle (145-150 degrees on instant read thermometer).
- Remove from the oven and cool for 30 minutes then put into the fridge to cool completely before adding the whipped cream topping.
For the topping:
- Combine the sugar and cream and vanilla and whip to stiff peaks. Spread on top of the key lime custard and chill for 30 minutes. Remove from the pan by pulling the parchment paper out on both sides, and cut into squares. Store in the fridge.