So happy you read the post! Thanks and Merry Christmas @pariza

Ingredients

Cream Filling:
4 egg whites
1 1/3 cups sugar
1/2 teaspoon salt
2 tablespoons palm syrup, maple syrup, or honey
1 cup (2 sticks) butter, at room temp (not cold or melted)
1 tablespoon vanilla extract
Doughnuts:
1/2 cup (1 stick) butter, softened
1 cup sugar
1 egg and 2 egg yolks
1 cup whole milk
1 1/2 teaspoons vanilla extract
1/2 teaspoon salt
1 teaspoon baking powder
1 1/2 cups flour
Instructions

Whisk egg whites, sugar, salt, and syrup in a small saucepan and place over your lowest setting on smallest burner. (most recipes call for putting your mixing bowl over a pot of boiling water instead so you can do that if you're worried about scrambling your eggs) Stir for 3 to 4 minutes over heat until sugar is dissolved. (If you have a candy thermometer and you want to use it you should wait until it's between 140 and 160 degrees F [60 - 70C]). Remove from heat and pour into the bowl of a stand mixer. Allow it to cool for about 5 minutes, then start beating on low speed and increase speed a little after every minute for about 5 minutes. Now turn onto high speed and beat until stiff peaks form. It needs to be very stiff if you push it to one side and it doesn't stay then it's not stiff enough Here's the tricky part, change to your beater attachment and add the butter to the bowl. Turn onto the lowest setting and let it mix nice and slow until it's done. (At first it will look all separated and weird but don't freak out, that's supposed to happen. Just let it keep mixing until it gets thick and delightfully fluffy. Add vanilla and beat until mixed. See, you did it!
Preheat oven to 350 degrees F (180 C) and grease 2 non-stick, 6-count, doughnut pans well with oil. Beat butter and sugar together in mixing bowl (no need to wash after the filling) until creamed. Beat in eggs and milk, then add salt, baking powder, vanilla, and flour and mix until smooth.
Pour scoops of batter into donut pans and fill to the line. Bake for 15 to 18 minutes until just starting to brown on top. Remove and cool completely, then loosen from pan (I find the side of a spoon works well for this).
Fill a pastry bag, fitted with long narrow tip, with your filling. Use chopstick or skewer to poke 3 - 4 holes around the doughnuts then pipe filling sideways into doughnuts. Serve as soon as possible after piping because the doughnuts will absorb the cream filling after a while.