Lightly oil a 6-cup round bowl or mold (the smaller the diameter at the top the better) and line it as smoothly as possible with plastic wrap, leaving a small overhang. Measure the diameter of the bowl and make note of it. You will need a round cake base of this size for the bottom of the Charlotte. Note: If the diameter of the top of your 6 cup bowl is very wide, you may want to make an additional 1/2 recipe of the cake in a smaller pan to make sure there is enough for the roll as well as the base. Alternately, you can use a smaller bowl.

Make the Biscuit Roulade cake in a sheet pan as directed in the recipe. As soon as the cake has finished baking, slide it out of the pan onto a flat surface using the parchment to help move it. Flip the cake onto a clean dishtowel and carefully remove the parchment paper.

While the cake is still hot, you will need to set aside a piece for the base and roll the remainder in a towel as described below.

Cut off a piece from one of the ends just wide enough to cut the top from later as shown in the photo below. Set this piece aside to cool. After this piece has cooled, cut it with shears or a sharp knife into the circle for the Charlotte base.

While the cake is still hot, roll the remaining piece of cake up tightly in the dishtowel. Roll from the longest side with the darkest side of the cake on the inside. Cool the rolled cake/towel on a rack.

When ready to fill, gently unroll the cake and leave it on top of the towel. Spread up to ½ cup of raspberry jam in a thin layer on top of the cooled cake, leaving it on the towel. The jam should look like it’s barely covering the cake).

Roll up the cake as tightly as you can about 1/3 of the way and then use the towel to pull the roll towards you and press on the other side of the roll with a bench scraper or your hands to help make the roll tight as you continue to use the towel to help roll the cake all the way up. The completed roll should be about 2” in diameter. It is important to get this roll as tight as possible as you do not want gaps in the spirals.

Wrap the roll tightly in plastic wrap and then foil and freeze until firm enough to slice, at least a couple of hours. If desired, the roll and the base can be frozen for a few weeks before you make the rest of the Charlotte.

When the roll is firm, cut it into ¼ inch slices with a small, serrated knife. You want to get as many spirals as possible, so be careful to evenly cut the slices as close to ¼ inch as you can. Work quickly so the cake roll doesn’t thaw and soften too much.

To line the bowl, place 1 slice in the center and place other slices around it as tightly as possible to try to avoid gaps.

The width of your mold and the width of your slices will determine how far up the mold you can get. You may need to cut the slices in half or smaller to fit the last rows if your slices go all the way up the mold. My bowl was fairly wide, so my cake slices did not go all the way up to the top of the bowl with what I had left over after cutting the base circle. If your spirals do go all the way up, trim the last ones even with the edge of the bowl. If not, you can trim them when you put in the cream.

Adjust the spirals to eliminate gaps, but it may not be possible to make it fit perfectly. If there are any gaps between the spirals, plug them with a small amount of the remaining raspberry jam or some trimmings from unused spirals. If you are using a glass bowl, you can hold it up to the light and see where light comes through. You want to plug these spots to prevent the Bavarian Cream from leaking through.

Cover the lined bowl tightly and place it in the refrigerator until the filling is ready.

Make the Bavarian cream and spoon it into the lined bowl until it comes up to the top of the bowl or just to the place the top spirals last touch each other.

Trim the top spirals even above the cream if necessary.

Place the cake round on top of the cream and touching the edge of the spirals.

Press down gently on the edges of the cake circle so it makes contact with the edge of the spirals.

Cover tightly and refrigerate until set, at least 8 hours.To unmold, invert onto a plate and lift away the bowl, tugging gently on the plastic wrap to release it. To prevent drying out, leave the plastic wrap in place until serving. Decorate with whipped cream and fresh fruit