Cream and raspberry jam cake roll

It's out of sheer curiosity that I decide to try out this cake. I love this new experiment. The recipe is from the KAF cookbook. I reduce the sugar from 3/4 cup to 1/2 cup. This is about the right amount of sugar for a good sponge cake.

Recipe: Cream and raspberry jam cake roll (1 roll)

Ingredients:
Sponge cake
- 3/4 cup KAF unbleached all-purpose flour
- 3/4 tp baking powder
- 1/4 tp salt
- 4 eggs
- 1/2 cup sugar
- 1 tp vanilla extract
Filling
- 1/2 cup heavy whipping cream
- 2-3 TB confectioner's sugar
- 2-3 TB raspberry preserve

Results:
11:05am, cake ingredients ready and pan lined with parchment paper (without grease):

11:28am, dry ingredients sieved, eggs ready to beat:

11:31am, sieved dry ingredients:

11:34am, egg beaten until foamy:

11:34am, 1/4 cup of sugar sprinkled onto egg while beating:

11:35am, all of the 1/2 cup of sugar added to the egg while beating:

11:36am, beating continued for 2 minutes, at low setting:

11:37pm, beating continued for 3 minutes, with increasing speed:

11:38am, beating continued for 4 minutes, at medium setting:

11:38am, state of the mixture:

11:39am, beating continued for 5 minutes at medium high speed:

11:40am, state of the mixture:

11:42am, beating continued for 7 minutes, at medium high speed:

11:42am, batter beaten until it stands momentarily when the whisk is lifted up:

11:45am, folding in dry ingredients:

11:59am, done folding in of flour, done slowly and gently, taking 15 minutes:

11:59am, vanilla added and mixed in:

12:02pm, batter poured into pan:

12:03pm, batter height in pan:

12:03pm, to bake at 400F, middle rack:

12:10pm, paper towel dusted with confectioner's sugar:

12:18pm, sheet cake baked for 18 minutes:

12:18pm, sheet cake's top:

12:19pm, sheet cake's corner:

12:19pm, sheet cake's edge:

12:19pm, sheet cake turned out onto paper towel:

12:20pm, parchment paper easily peeled off bottom:

12:23pm, with the hard edges, the sheet cake cannot be folded. Thus the two edges at the long side are trimmed off:

12:24pm, sheet cake rolled:

12:25pm, the edge of trimmed side:

12:25pm, clean knife:

12:29pm, roll to cool:

3:51pm, ingredients for cream ingredients:

3:54pm, 1/2 cup heavy cream and 2-3 TB confectioner's sugar to be beaten:

3:56pm, mixture beaten 5 minutes:

3:57pm, cream filling done:

3:59pm, raspberry jam filling:

3:59pm, sheet cake unrolled:

4:02pm, jam spread onto sheet cake:

4:04pm, cream spread onto sheet cake:

4:06pm, leftover cream:

4:06pm, sheet cake rolled up:

4:06pm, two ends of cake when rolled back up:

4:09pm, end trimmed:

4:10pm, top:

4:11pm, bottom:

4:10pm, crack:

4:12pm, wrapped up to chill:

Overnight, 8:26am:

Overnight, 8:26am, heel:

Overnight 8:30am, top when sliced (yielding 9 slices):

Overnight, 8:30am, side when sliced:

Overnight, 8:31am, interior:

Overnight, 8:31am, to serve:

Observations:
1. I must have over-baked the cake. It comes out golden brown, but just a bit too hard to roll up. Next time I should just bake for 12 to 14 minutes.
2. I reduce the sugar level by a third. The resultant cake is very nice and spongy that is not overly sweet.
3. As the cake has a hard time rolling up, I have to use more cream to fill in the gap of the roll.
4. When I taste the cake after overnight chilling, the sponge is obviously overcooked as it is too dry. Since the cake is so dry, it takes a few days before the roll becomes soft (as the sponge cake slowly absorbs moisture from the jam and the cream). I really need to shorten the baking time next time.
5. For my own personal taste, the filling may use less sugar. About 1 TB of confectioner's sugar will be good enough. The amount of sugar in the sponge cake is about right.