Baking – How to prevent pear juice from soaking into pastry dough

This is because you are using a microwave. In theory, if you could turn off the microwaves in the microwave oven, you could use the convection function to bake things. In practice, we have had several questions which indicate that this is not how convection microwaves work. They keep nuking your dough, making it inedible. In your case, they are cooking all the moisture locally, resulting in mini-steam-explosions which create blisters, and a dried out, hard and crispy dough.

I am sorry, but there is no way you can bake with a microwave, not short pastry, and not other things. One exception might be quickly eaten "microwave cupcakes" which don't have much flour to start with and are baked for a very short time. I have seen people claim that they work, but never actually tried them.

For baking, you need a non-microwaving oven. The cheapest solution is a toaster oven with a 30x30 cm inner size, they are somewhat trickier to use than a big oven, but good enough for a small budget.

I would start by rolling the pastry dough thinner; I often have my dough too thick the first time or two that I work with a recipe. Keep the dough cold to make it easier to work with.

Next, I would try different oven times and temperatures. Try a temperature 25-50 degrees (F) higher, and pull the rolls out 30 seconds to one minute sooner. The nice thing about playing with oven times and temps is that you can go through many tests quickly by just putting a few of the items in for each time/temp combination. (Extra mass in the oven, such as a pizza stone or even some bricks, will help keep the oven temp more steady.)

If the outside of your rolls are getting over done before the inside is done, try chilling the rolls in the refrigerator for 30 minutes or so before baking.