If I was to pipe a sheet cake pan lined with parchment could I use a CHOUX pastry to make one big pastry sheet then repeat it so I can have 2 layers Im thinking of pastry, pastry cream, pastry, pastry cream and then chocolate ganache .Basically a deconstructed Eclair WILL THIS WORK???? Darn where is LindaC when you need her :)

No. In an éclair or a cream puff, the choux paste has expanded because of steam. In a whole sheet of it, steam expansion would be iffy and spotty. Even if it worked, it would taste very different, because the taste of an éclair depends very much on the browned edges of the (fairly small) eclair. In the big sheet you'd have much less edge. If there must be a sheet, I think the best way would be to make bake éclairs, fill them, and assemble them into a sheet cake. Not much point, though.
Would you brother be just as pleased by Napoleon layers?

Your probably right...Im NOT looking to stuff the pastry sheet im looking to use it as a layer for flavor. Phyllo or Puff Pastry probably wouldn't taste the same. Hmmm if I used puff pastry then its actually a Napolean even if you put chocolate on top right?

Yeah, and who would not love an all-chocolate-top Napoleon?
There is probably some maximum size for getting good results with sheets of puff pastry. I don't know if a half-sheet (13 x 18) is doable. Maybe someone else has experience with doing that. I'd probably stay in the quarter-sheet size range.

I don't think it will work for the same reason CC posted but here's another idea for the eclair lover. You could get the largest Christmas tree shaped styrofoam cone at a craft shop and cover it with foil.

Then make or buy the miniature eclairs and pin them solidly over the cone. After it's covered, you could pipe a birthday greeting with contrasting frosting over the chocolate.

Easy to portion out for serving too.

Have a look at this. It's a stack of profiteroles stuck together with caramel. It's called une pièce montée. A lovely celebration cake.

Here is a link that might be useful: piece montee

Can you make a Boston Cream Pie instead? It shouldn't be too difficult to make a sheet cake, split it in two, give a little hollow to each piece and fill with pastry cream. Put it together and top with ganache.

If you want that éclair experience, just make little ones and do like ruthanna said. They'll still be good!

Even though it's "downmarket" and perhaps declasse', I'd do the graham cracker one. Tastes great! No leftovers at our house.
You can make your own filling rather than use a pudding mix and use real cream instead of cool whip.

Here is a link that might be useful: Eclair cake

This one looks good:

Cream Puff Chocolate Eclair Cake

Rating: 5

Prep Time: 20 minutes

Cook Time: 35 minutes

Total Time: 55 minutes

Cream Puff Chocolate Eclair Cake

Ingredients

Pastry:
1/2 cup (1 stick) unsalted butter
1 cup water
1 cup unbleached all purpose flour
4 large eggs
Chocolate Filling:
2 ounces semisweet chocolate
2 tablespoons butter
1 teaspoon vanilla extract
1 cup confectioners' sugar
3 tablespoons hot water
Cream Filling:
4 cups milk
8 oz. cream cheese, softened
2 large (5.1 oz) pkgs instant vanilla pudding (or 3 small, 3.4 oz)
Topping:
1 8-ounce container Cool Whip
Chocolate syrup

Instructions

Preheat oven to 400 F.
For the Pastry:
In a large heavy saucepan, heat butter and water to boiling over medium-high heat. Add flour and reduce heat to low. Cook and stir until it forms a ball and pulls away from the pan. Remove from heat and transfer to a large bowl. Beat in eggs, one at a time, beating well after each egg.
Spread in bottom and up the sides of an ungreased 9x13 inch pan. Bake at 400 degrees F for 35 minutes. Cool completely.
For the Chocolate Filling:
Melt chocolate and butter in the microwave on high for 1 minute. Stir. Continue heating at 20 second intervals until smooth. Stir in vanilla. Sift in the powdered sugar, a little at a time, stirring as you go. Dribble water in to the mixture until smooth and spreadable (you may or may not use all the water). Spread over the cooled pastry.
For the Cream Filling:
In mixing bowl beat the cream cheese until fluffy. Slowly and gradually add the milk while still beating. Once these are well combined, add pudding mix and beat until thickened. Spread over chocolate layer in cooled pastry.
Top with whipped topping, and draw lines of chocolate syrup across the top, then run a knife down the top in the opposite direction of the syrup lines, about every 2 inches. Keep refrigerated until ready to serve.

Here is a link that might be useful: Eclair Cake

Thanks for essential information bt for making new receipe We require new electrical appliances that will help us to make our work easier.which is avilable at reasonableprices.