The first thing you can put together from pastry cream and cream puff pastry is a profiterole. Technically, there are a number of things with which you can fill a profiterole. Here, I have used the pastry cream, but you could also use ice cream or whipped cream. Additionally, you can flavor the pastry or whipped cream any way you wish... lemon, chocolate, almond; the choices are endless.
With profiteroles, you want to pipe a fairly good sized blob of pastry. I usually pipe them to the size of a golf ball. If you want to fit a scoop of ice cream inside, you'll want to pipe them even larger. When they first come out of the oven, slice them open so that there is a large base and a small cap. Bake at 425° F until the pastry is puffed, dry, and deeply golden. Slicing them open immediately helps release the steam inside so that they cool without softening up too much. This is especially important for the profiteroles because they are fairly large in size.
You can top profiteroles with whatever delicious sauce you would like, but chocolate is classic. Putting together the chocolate sauce is super easy. Simply melt a bit of chocolate in a bowl in the microwave. Stir in a little heavy cream and any flavoring you might be interested in, such as liquor or extract. I like to put it into a squirt bottle so it's easy to make a very attractive dessert.
The last component I had on the dessert pictured above is a fruit sauce. I used a raspberry sauce made by blending thawed frozen raspberries, sugar, and a little lemon juice. I put the raspberry sauce in a squirt bottle, too.
To assemble the dessert, squirt a little bit of the chocolate sauce in the middle of a plate to anchor the cream puff and help it sit straight. Place the base of the cream puff on the chocolate and fill with your choice of filling. You can pipe or spoon in the filling. Put the cap on and drizzle chocolate sauce over the top. Squirt small blobs raspberry sauce around the perimeter of the cream puff and use the tip of a knife the drag some of the sauce to make a pretty comma shape. I tried using a toothpick, but I did not find it was substantial enough to do the job properly.
Although you'll want to serve immediately for best results, you can prepare all of the components ahead of time and simply assemble at the last moment.