1. Melt butter in saucepan and let stand until cool.
2. Place flour in bowl and make a well in the flour. Place eggs and egg yolk in well and stir carefully, absorbing, some flour from the edges. Start adding milk, stirring continuously with a wooden spoon until all flour is incorporated.
3. Add cooled butter and salt. Mix well and place the bowl in a cool place for 1 hour to rest.
4. Then, use 1/8 cup (or 2 Tbsp.) batter per crepe. Brush crepe pan with oil before cooking each one. Pan is ready when drops of water bounce and dance.
5. Stack as they are finished, placing a paper towel between each two (to roll up over filling). Use one per roll; two per serving.
1. Combine blueberries or strawberries and sugar in saucepan and bring to boil.
2. Mix water and cornstarch. Mix well and add to mixture. Cook over medium heat until thick. Remove and cool.
3. Fold into center of crepe and roll.
4. Top with whipped topping.