Pre-heat oven to 350F.

Line 18 cupcake molds with a cupcake liner or grease them with butter and flour if they aren’t silicon. Set aside.

Sift together the flour, baking powder, baking soda, and salt. Set aside.

In a mixer, cream butter for 1 minute. Add sugar and cream on high for another 2 minutes until mixture is very fluffy and whitened in color.

Add eggs, one a time, waiting for the first egg to be incorporated before adding the next egg.

Add vanilla. Mix to combine.

Add strawberry puree, and yogurt.

Mix until combined.

Add dry mixture and fold with a spatula until incorporated. Don’t overmix.

Pour evenly in the cupcake pans.

Bake for about 15 minutes, rotating in between.

Cupcakes will be done baking once you can gently poke the top of the cupcake with your finger and it will spring back.

Set aside to cool.

Whisk milk, half of the sugar, and the vanilla bean seeds (and you can add the pod in there too to help infuse the milk). If you aren’t using vanilla bean seeds, and using the vanilla extract instead, you want to wait to add it at the very end.

Bring mixture almost to a boil. Turn the heat off. Let it infuse for about 20 minutes. (If not using vanilla beans, skip this step.)

If you let your milk mixture infuse, you want to quickly re-heat it for just a little bit before proceeding.

Whisk egg yolks, plus half of the sugar, cornstarch, and flour in a bowl.

Whisk until mixture is very lightened in color, and a bit runny.

Add a couple of tablespoons of the hot milk to egg yolks, while whisking non-stop.

Add another couple of tablespoons. Keep doing this while you whisk the mixture. You are tempering the eggs, and avoiding them to cook, by slowly raising the temperature.

At the end you can just pour the rest of the milk in.

Put mixture back in the pot where you heated the milk, and make sure to strain it before, so you can catch any bits of eggs that may have cooked.

Then, use a spatula or wooden spoon to stir your custard over medium heat. Don’t stop stirring, don’t look away, you don’t want it to overcook.

Keep cooking and stirring until it starts to get kind of grainy, and then it will start to get really thick and smooth. When the whole mixture is creamy, smooth, and thick, you can turn the heat off.

Add butter and mix until melted and incorporated.

Transfer mixture to a heat-proof bowl. Let it sit for about 10 minutes and then add the vanilla extract if that’s what you are using.

Cover with plastic wrap directly on the surface of the cream. Place it in the fridge until completely cooled down.

Place strawberries, and sugar in a small saucepan. Bring to a boil over medium heat, stirring constantly, and let it boil for 5-10 minutes. If the mixture is getting too thick, add a tablespoon of water or so.

Let mixture cook down, regulate the heat to keep it at a gentle simmer.

Once mixture has cooked down and it’s syrupy and the sugar has melted, you can dissolve the cornstarch in water and add that to the strawberry mixture, stirring and cooking over medium heat.

Let mixture simmer and get thick, for about 10 minutes.

Remove and let mixture cool down in the fridge all the way before using it.

Cream butter in the bowl of a mixer, at medium-high speed for 2 minutes.

Turn mixer off. Add sugar. Mix on low until sugar is incorporated.

Cream for another 1 minute.

Add vanilla and mix to combine. If texture is too stiff, add the heavy cream. Otherwise, it’s ready to pipe.

Place frosting in a bag lined with your favorite tip.

Remove the center of each cupcake with a spoon.

Pipe some of the Buttercream Frosting around the edges of the cupcake, leaving the middle and the hole in the center of the cupcakes open.

Now place the pastry cream in a piping bag and pipe some in the middle of the cupcake all the way to the top of the frosting.

Alternatively you can do this with a spoon.

Then, spoon a tiny bit of strawberry jelly on top of pastry cream.

Top with chopped fresh strawberries, and I also used a little mint leaf to decorate the top.

Cupcakes will keep for up to 3-4 days in a closed container, in the fridge.